[keycloak-user] Realm resolution by username

Hi all, I'm using keycloak in a multi-tenant scenario where each tenant is a realm and the clients are duplicated across them. The username for each user is an email address of username(a)tenant.tld Is there any way to use the @tenant.tld part of the email address as a realm resolver and have all users access the system via the same login page? Thanks, Ian.