OIDC login ends with 403. You are not allowed to access this resource.

I am not able to figure out, how to correctly setup SSO via OIDC. After following every step in how-to: OIDC SSO | Mendix Documentation when i click on button in my app adding oauth/v2/login, the error appears on the callback url /oauth/v2/callback I use AzureAD, and configuring it in the app was also not a problem with secrets etc. What could be the issue?  
1 answers

Did you add the callback url in your app registration in Azure?

It needs to be listed in Authentication in redirect URIs