[keycloak-user] Identity Provider / First Broker Login Flow Hooks

Hey together, I would like to integrate with an external Identity Provider and I wonder about the best way to hook into this process? As soon as the external IP authorizes the user with a valid token I would like to do some internal setup calls and link metadata to the user (attributes) being created by Keycloak. I know it is possible to extend Keycloak with custom IdentityProviderMapper extensions but I would like to validate if they are also meant to execute async http requests? If not, are there any other options better suited for this use case? Thanks for any feedback Andreas