Okta-spring-boot-starter - Unable to resolve Configuration with provided issuer of

Questions OAuth/OIDC
1

Hello! I am having issues with getting the okta-spring-boot-starter setup working. In this case, am writing backend endpoints in order to support a client side application.

Here are the instructions I’m following: https://github.com/okta/okta-spring-boot#supporting-client-side-applications—oauth-implicit-flow

I’ve included my full stack trace below, but I’m wondering whether the IllegalArgumentException with the error message Unable to resolve Configuration with the provided issuer of.." is the root issue here. When I try navigating to this url https://slackcorp.okta.com/oauth2/default` I get a 404.

Okta application details

application.properties
okta.oauth2.issuer=https://slackcorp.okta.com/oauth2/default
okta.oauth2.client-id=0oaq60t2y0hSwuaHR0x7

Stack trace:
. ____ _ __ _ _
/\ / ’ __ _ () __ __ _ \ \ \
( ( )__ | '_ | '| | ’ / ` | \ \ \
\/ )| |)| | | | | || (| | ) ) ) )
’ || .__|| ||| |_, | / / / /
=========||==============|/=////
:: Spring Boot :: (v2.3.1.RELEASE)

2021-03-09 10:47:36.679  INFO 21416 --- [           main] com.example.demo.DemoApplication         : Starting DemoApplication on SFO-M-SARAHJIANG01 with PID 21416 (/Users/sarahjiang/Desktop/de/Slack.0 Server/testSpringOkta/target/classes started by sarahjiang in /Users/sarahjiang/Desktop/de/Slack.0 Server/testSpringOkta)
2021-03-09 10:47:36.682  INFO 21416 --- [           main] com.example.demo.DemoApplication         : No active profile set, falling back to default profiles: default
2021-03-09 10:47:37.582  INFO 21416 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8081 (http)
2021-03-09 10:47:37.590  INFO 21416 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
2021-03-09 10:47:37.591  INFO 21416 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet engine: [Apache Tomcat/9.0.36]
2021-03-09 10:47:37.652  INFO 21416 --- [           main] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2021-03-09 10:47:37.653  INFO 21416 --- [           main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 914 ms
2021-03-09 10:47:38.719  WARN 21416 --- [           main] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'org.springframework.boot.autoconfigure.web.servlet.WebMvcAutoConfiguration$EnableWebMvcConfiguration': Unsatisfied dependency expressed through method 'setConfigurers' parameter 0; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'org.springframework.security.config.annotation.web.configuration.OAuth2ClientConfiguration$OAuth2ClientWebMvcSecurityConfiguration': Unsatisfied dependency expressed through method 'setClientRegistrationRepository' parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'clientRegistrationRepository' defined in class path resource [org/springframework/boot/autoconfigure/security/oauth2/client/servlet/OAuth2ClientRegistrationRepositoryConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.security.oauth2.client.registration.InMemoryClientRegistrationRepository]: Factory method 'clientRegistrationRepository' threw exception; nested exception is java.lang.IllegalArgumentException: Unable to resolve Configuration with the provided Issuer of "https://slackcorp.okta.com/oauth2/default"
2021-03-09 10:47:38.722  INFO 21416 --- [           main] o.apache.catalina.core.StandardService   : Stopping service [Tomcat]
2021-03-09 10:47:38.733  INFO 21416 --- [           main] ConditionEvaluationReportLoggingListener : 

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2021-03-09 10:47:38.743 ERROR 21416 --- [           main] o.s.boot.SpringApplication               : Application run failed

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'org.springframework.boot.autoconfigure.web.servlet.WebMvcAutoConfiguration$EnableWebMvcConfiguration': Unsatisfied dependency expressed through method 'setConfigurers' parameter 0; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'org.springframework.security.config.annotation.web.configuration.OAuth2ClientConfiguration$OAuth2ClientWebMvcSecurityConfiguration': Unsatisfied dependency expressed through method 'setClientRegistrationRepository' parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'clientRegistrationRepository' defined in class path resource [org/springframework/boot/autoconfigure/security/oauth2/client/servlet/OAuth2ClientRegistrationRepositoryConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.security.oauth2.client.registration.InMemoryClientRegistrationRepository]: Factory method 'clientRegistrationRepository' threw exception; nested exception is java.lang.IllegalArgumentException: Unable to resolve Configuration with the provided Issuer of "https://slackcorp.okta.com/oauth2/default"
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredMethodElement.inject(AutowiredAnnotationBeanPostProcessor.java:723) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:130) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:399) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1422) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:594) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:226) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:893) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:879) ~[spring-context-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:551) ~[spring-context-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:143) ~[spring-boot-2.3.1.RELEASE.jar:2.3.1.RELEASE]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:758) ~[spring-boot-2.3.1.RELEASE.jar:2.3.1.RELEASE]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:750) ~[spring-boot-2.3.1.RELEASE.jar:2.3.1.RELEASE]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) ~[spring-boot-2.3.1.RELEASE.jar:2.3.1.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) ~[spring-boot-2.3.1.RELEASE.jar:2.3.1.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1237) ~[spring-boot-2.3.1.RELEASE.jar:2.3.1.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226) ~[spring-boot-2.3.1.RELEASE.jar:2.3.1.RELEASE]
	at com.example.demo.DemoApplication.main(DemoApplication.java:21) ~[classes/:na]
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'org.springframework.security.config.annotation.web.configuration.OAuth2ClientConfiguration$OAuth2ClientWebMvcSecurityConfiguration': Unsatisfied dependency expressed through method 'setClientRegistrationRepository' parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'clientRegistrationRepository' defined in class path resource [org/springframework/boot/autoconfigure/security/oauth2/client/servlet/OAuth2ClientRegistrationRepositoryConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.security.oauth2.client.registration.InMemoryClientRegistrationRepository]: Factory method 'clientRegistrationRepository' threw exception; nested exception is java.lang.IllegalArgumentException: Unable to resolve Configuration with the provided Issuer of "https://slackcorp.okta.com/oauth2/default"
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredMethodElement.inject(AutowiredAnnotationBeanPostProcessor.java:723) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:130) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:399) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1422) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:594) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:226) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.addCandidateEntry(DefaultListableBeanFactory.java:1522) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1486) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveMultipleBeans(DefaultListableBeanFactory.java:1375) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1262) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1224) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredMethodElement.inject(AutowiredAnnotationBeanPostProcessor.java:715) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	... 20 common frames omitted
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'clientRegistrationRepository' defined in class path resource [org/springframework/boot/autoconfigure/security/oauth2/client/servlet/OAuth2ClientRegistrationRepositoryConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.security.oauth2.client.registration.InMemoryClientRegistrationRepository]: Factory method 'clientRegistrationRepository' threw exception; nested exception is java.lang.IllegalArgumentException: Unable to resolve Configuration with the provided Issuer of "https://slackcorp.okta.com/oauth2/default"
	at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:655) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:635) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1338) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1177) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:557) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:517) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:323) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:226) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:321) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:276) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.addCandidateEntry(DefaultListableBeanFactory.java:1522) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1486) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveMultipleBeans(DefaultListableBeanFactory.java:1375) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1262) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1224) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredMethodElement.inject(AutowiredAnnotationBeanPostProcessor.java:715) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	... 36 common frames omitted
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.security.oauth2.client.registration.InMemoryClientRegistrationRepository]: Factory method 'clientRegistrationRepository' threw exception; nested exception is java.lang.IllegalArgumentException: Unable to resolve Configuration with the provided Issuer of "https://slackcorp.okta.com/oauth2/default"
	at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:650) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	... 52 common frames omitted
Caused by: java.lang.IllegalArgumentException: Unable to resolve Configuration with the provided Issuer of "https://slackcorp.okta.com/oauth2/default"
	at org.springframework.security.oauth2.client.registration.ClientRegistrations.getBuilder(ClientRegistrations.java:207) ~[spring-security-oauth2-client-5.3.3.RELEASE.jar:5.3.3.RELEASE]
	at org.springframework.security.oauth2.client.registration.ClientRegistrations.fromIssuerLocation(ClientRegistrations.java:138) ~[spring-security-oauth2-client-5.3.3.RELEASE.jar:5.3.3.RELEASE]
	at org.springframework.boot.autoconfigure.security.oauth2.client.OAuth2ClientPropertiesRegistrationAdapter.getBuilderFromIssuerIfPossible(OAuth2ClientPropertiesRegistrationAdapter.java:83) ~[spring-boot-autoconfigure-2.3.1.RELEASE.jar:2.3.1.RELEASE]
	at org.springframework.boot.autoconfigure.security.oauth2.client.OAuth2ClientPropertiesRegistrationAdapter.getClientRegistration(OAuth2ClientPropertiesRegistrationAdapter.java:59) ~[spring-boot-autoconfigure-2.3.1.RELEASE.jar:2.3.1.RELEASE]
	at org.springframework.boot.autoconfigure.security.oauth2.client.OAuth2ClientPropertiesRegistrationAdapter.lambda$getClientRegistrations$0(OAuth2ClientPropertiesRegistrationAdapter.java:53) ~[spring-boot-autoconfigure-2.3.1.RELEASE.jar:2.3.1.RELEASE]
	at java.base/java.util.HashMap.forEach(HashMap.java:1336) ~[na:na]
	at org.springframework.boot.autoconfigure.security.oauth2.client.OAuth2ClientPropertiesRegistrationAdapter.getClientRegistrations(OAuth2ClientPropertiesRegistrationAdapter.java:52) ~[spring-boot-autoconfigure-2.3.1.RELEASE.jar:2.3.1.RELEASE]
	at org.springframework.boot.autoconfigure.security.oauth2.client.servlet.OAuth2ClientRegistrationRepositoryConfiguration.clientRegistrationRepository(OAuth2ClientRegistrationRepositoryConfiguration.java:49) ~[spring-boot-autoconfigure-2.3.1.RELEASE.jar:2.3.1.RELEASE]
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na]
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
	at java.base/java.lang.reflect.Method.invoke(Method.java:566) ~[na:na]
	at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154) ~[spring-beans-5.2.7.RELEASE.jar:5.2.7.RELEASE]
	... 53 common frames omitted

I have also tried omitting the /oauth2/default like below:
okta.oauth2.issuer=https://slackcorp.okta.com
okta.oauth2.client-id=0oaq60t2y0hSwuaHR0x7

And get the error,
Parameter 0 of method oauth2SecurityFilterChain in com.okta.spring.boot.oauth.OktaOAuth2AutoConfig$OAuth2SecurityFilterChainConfiguration required a bean of type ‘org.springframework.security.config.annotation.web.builders.HttpSecurity’ that could not be found.

Action:
Consider defining a bean of type 'org.springframework.security.config.annotation.web.builders.HttpSecurity' in your configuration.

This is not mentioned in setup instructions, so I’m not clear on what the correct setup should be.

2

Since you’re trying with a corporate production org, you may need to create your Authorization Server and you will need to get API Access Manager as a Product.

Try out your code with the developer account org and it should work. See signup instructions at developer.okta.com. Or, try out the Okta CLI tool.

3

Hi @sjiang,

You’re having this issue because you do not have API Access Management on this account and without it, you will not be able to use custom authorization servers. The issuer you are trying to use (https://slackcorp.okta.com/oauth2/default) is a custom authorization server.

You could instead, use your org authorization server but this has limited capabilities.

For example, if you try this endpoint you’ll see that data is returned (this is using your org authorization server) https://slackcorp.okta.com/.well-known/oauth-authorization-server.

Try setting your issuer as https://slackcorp.okta.com and see if that resolves the error.

1 Like
4

I mentioned in my original post that I tried omitting the `/oauth2/default and just using https://slackcorp.okta.com and got an error. Can you explain why I might be seeing that error?

5

If you take a look at the docs for the /authorize endpoint, you will see that there are a few parameters that are required as part of the request. You will see an error without these.