Test Application-initiated sign-in flow

Sign out of your administrator account in your development org and also sign out of your application.
In your browser, begin the sign-in process to your application, either through your application's sign-in button or directly by pasting the Login redirect URI into your web browser address bar. Regardless of which method you choose, your browser must end up at the Okta-hosted sign-in page.
Sign in to your regular user account on the Okta-hosted sign-in page.
Confirm that Okta successfully redirects back into your application.

If you run into issues with your sign-in process, you can try the following to troubleshoot the issues:

In the Admin Console of your Okta development org, navigate to Reports > System Log and examine any failure messages reported.
Open the developer console of your web browser and examine any status messages related to your authentication request. The console errors have status codes in the 4XX range. Investigate and resolve any error messages generated by your sign-on request.
Send an email to developers@okta.com, or post your questions on either the Okta developer forum or on Stack Overflow.