Oauth2 Proxy is used to provide the redirection / cookie check in order to enforce JWT presence even via web browser

General concept:
https://medium.com/@senthilrch/api-authentication-using-istio-ingress-gateway-oauth2-proxy-and-keycloak-part-2-of-2-dbb3fb9cd0d0
https://discuss.istio.io/t/how-to-implement-istio-authorization-using-oauth2-and-keycloak/13707

Add Oauth2-Proxy client to Keycloak-Realm:

https://oauth2-proxy.github.io/oauth2-proxy/docs/configuration/oauth_provider#keycloak-oidc-auth-provider

https://discuss.istio.io/t/how-to-implement-istio-authorization-based-on-keycloak-user-role/13716

https://doc.primekey.com/ejbca/ejbca-operations/ejbca-operations-guide/ca-operations-guide/oauth-provider-management/configuring-audience-claims