[keycloak-user] Recommended approach to "Passing thru Custom URL parameters" on AUTH

Hi, I'm trying to find the best approach to passing thru custom url parameters from our application to keycloak and for use in the keycloak freemarker templates (login/otp etc) http://localhost:8080/auth/realms/lobby/protocol/openid-connect/auth?clie... This then successfully loads the login page within Keycloak BUT the "session_state" and "custom_param" params are lost and not available for use in the freemarker templates.. Whats the best approach to expose these custom params to login.ftl/loginOTP.ftl etc ?