Looking for ready to use Identity server Oauth solution to be used in my project. -- 2

I am looking for a ready-to-use solution for identity server OAuth that I can use in my project. Specifically, the authentication type I'm looking for is OpenID Connect and it does not need single sign-on functionality. Additionally, the authorization must be role-based. I am in need of a secure software that is flexible and customizable, capable of successfully protecting and authenticating users within my project.

I am looking for ready to use Microsoft .Net API solution.