Spring boot user authenticate with keycloak (microservices)

Question

I'm trying to re-build monolith app with microservices. Now I'm trying to make in-app authorization based on JWT. Approximate diagram is next:

RootService uses to manage users (create, update, delete) and other different entities. So what I want to do is make user-authorization service with keycloak using RootService, so it should look something like this: In keycloak I created realm and one client for gateway service using next parameters:

Current client gives ability to generate JWT and communicate between service, but how can I manage user access with keycloak using roles and so one? Should I create another client and generate some token for gateway client or I can use same created client and can create users via keycloak?

If there is any good article or guide - I'll be grateful for some resources. Thanks for replies!