CORS Error with Okta React Sample – What Am I Missing?

[thiago.martins]

Hello, everyone!

I’m currently working on understanding SSO and have tried running the example found here: GitHub - okta-samples/okta-react-sample: React + Okta.

I managed to get the React frontend working, but I’m encountering an issue. When I click ‘login’, I receive the following error:

Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at https://dev-09774240-admin/oauth2/default/.well-known/openid-configuration. (Reason: CORS request did not succeed). Status code: (null).

Here is how I have configured Okta:

• Application Type: OIDC - OpenID Connect
• Application Type: Single-Page Application
• Sign-in Redirect URIs: http:// localhost:3000/login/callback
• Sign-out Redirect URIs: http:// localhost:3000

Could anyone help me troubleshoot this CORS issue?

Thanks!

[SitaRam]

To use Okta with your application running on localhost (assuming you are running locally for this testing), you need to add your localhost URL (e.g., http://localhost:4000) to the “Trusted Origins” list in your Okta Admin Console.

Navigate to Security > API > Trusted Origins, click “Add Origin”, enter your localhost URL, select “CORS” as the Type, and save.

This allows your local development environment to interact with Okta APIs properly.

[thiago.martins]

Thank you, @SitaRam !

I have added http://localhost:3000/ and http://localhost:3000. Also set the type to CORS and Redirect, but it still didn’t work.

The error appears when I call this function inside Home.jsx:

const login = async () => {
  await oktaAuth.signInWithRedirect(); // this line throws errors //
};

Thanks!!

[andrea]

Try updating your ISSUER value to https://dev-09774240.okta.com/oauth2/default (removing -admin and adding the missing .okta.com). Does it still fail?

[ruslan-akhm]

I noticed your Sign-in and Sign-out redirect URIs have extra space in between http:// and localhost:3000. Maybe it is just a copy/paste error or a typo.
Can you check if you have that space in an actual config?