Serving access tokens to users already logged in with third party identity provider

Hi everyone,
we want to use Keycloak to manage access to our resource server thats being used by few different applications. The users log in through third party identity provider and have valid access token from it.

How can we give them our access token without forcing another authentication through Keycloak?

Is there a way to exchange valid access token from idp for keycloak issued one?