What

Keycloak does many redirects, in order to allow for this some configuration is needed in keycloak
https://www.keycloak.org/docs/latest/server_installation/index.html#_setting-up-a-load-balancer-or-proxy
has the details.

How
During provision allow the user to tick a box that says this keycloak will be behind a proxy that will set then change the configuration as per the above doc (I don't think there are additional details needed)