Unable to use production account for SSO login


I have download a sample code for Okta SSO interation from https://github.com/oktadeveloper/okta-aspnet-mvc-example.git.

Below are the details that I have used:
ORG URI: https://durlabhcomputers.okta.com/oauth2/default
RedirectUri = http://localhost:8080/authorization-code/callback
PostLogoutRedirectUri = http://localhost:8080/Account/Login

Same source code with using credentials of production account does not running, while its working fine with development account: https://dev-967697-admin.oktapreview.com.

Please let me know what I have to do to make it running.

Depending on what you are building, you may need the API Access Management feature on your production organization.

Can you provide some more details about what this application is? Is it used by employees or external customers? Where will people go to log in?