[keycloak-user] Auth-Code-Flow over multiple microservices

Hi, I have a setup and a usecase that seems to be quite unique (according to my google search effords). I use a frontend consisting of pure java script (microservice 1). Behind that runs a backend created with java spring boot (microservice 2). To authenticate users I want to switch from the implict flow to the auth-code-flow for additional security. However, this additional security can not be achieved using a pure java script client... So I had the following idea: Integrating the backend into the auth-code-flow of the frontend. I was planing to let the request to the authorization-endpoint be handled by the frontend alone, but than proxy the request to the token endpoint through the backend (where the client secret is injected). Does the keycloak spring-boot-adapter provide any useful functionality for this usecase? Is this a good idea in general? I am thankful for any help or comment provided :) Best Bob