I am creating my very first OIDC auth application and am having a struggle getting it to work. I'm working with a vendor and have provided them everything they have needed thus far. They are to a point where we are "supposed" to be able to allow the app for the entire org, but I can't get it work.

When I click the login with OpenID, it takes me to a page with a 400 error , bad request with this error:

'redirect_uri' parameter must be a Login redirect URI in the client app settings:

Then it lists a url below to the actual app where I can make the change. The vendor had me put the url to the app in the redirect uri setting and that doesn't work. I found an article that had me look through the logs on the app and find the bad request. That's where I found the illegal_redirect_uri_enhanced error.

In looking at the error, and the support document, there is a very lengthy url listed, that according to the document, I copy and add as a redirect uri to the app. That doesn't work either. Is there something I need from the vendor to get this working (they seem to think it's on our end, which it very well may be), or is there somewhere else I can look to find the correct redirect uri?

Thanks for any help!!