Custom OIDC IdP that only validates external token with Public Key

Hi, i need to create an specific case of an Identy Provider OIDC using an external JWT token with token exchange.

The problem is that i only need/can validate the external jwt token using the publick key in PEM format, in other words i need to be able to do the validation without using authorization url and token url of the idp form.

The main problem im facing is finding and understanding how the form of the admin console of the idp oidc interacts with the source code, because im also pretty new in Java and Keycloak.

I dont know if anyone can give me an advice on how to apporach the solution, but everything is appreciated. Im using Keycloak 18.0.2