im an intern working on a project where we have a frontend using react and a backend using spring boot and we are trying to use keycloak
from every doc i have read i saw that the frontend should use keycloak form to login the user and then if its succefull we will only use the jwt to get the resources in our backend api
but my manager keeps insisting on using the backend api to communicate with keycloak and leave the frontend to only communicate with the api
he keeps mentionning authorization code
i honestly have no idea what to do i tried to find a tutorial but i can find anything
i tried to use admin-cli to login the user from an endpoint using his username and password but it didnt work for me either

what should i do ?
if anyone can give a detail process of how to do this i would appreciate it