Using the OAuth2 server as an identity provider in Keycloak

[aemaem]

Does anyone has experience in configuring the OAuth2 server, that it can be used as an Identity Provider in Keycloak? What needs to be configured in the OAuth2 server?

Keycloak would be the client further redirects the user to the OAuth2 server login. As far as I understand, in the OAuth2 server Keycloak has to be registered as a client with a redirect URI.

Then in Keycloak the OAuth2 server would be configured as an identity provider:

Would be great if someone could help me on this.