[keycloak-user] OIDC claims are not mapped on first login

I have configured an OIDC identity provider and added a few attribute Attribute Importer mappers, such as (claim -> attribute): preferred_username -> username email -> email However, on first login, Keycloak asks me to supply missing user information, including username and e-mail. Username is pre-filled with the sub-claim, everything else is empty. Did I miss some additional config? I also have a hardcode role which is working fine. Maybe I don’t have the properties right, but I can’t find a list of Keycloak user properties and how to access them through attribute mappers. Rens