The keycloak team stopped supporting Wildfly 25 in favour of the built in elytron OIDC client. The keycloak adapter had a feature for resolving different realm configuration based on the URI. https://www.keycloak.org/docs/latest/securing_apps/index.html#_multi_tenancy

This is currently not possible with the new elytron OIDC client.

Quarkus has a similar feature for resolving realm configuration: https://quarkus.io/guides/security-openid-connect-multitenancy

It would be nice to see future wildfly releases support this kind of environments.