[keycloak-user] username to be used for importing users

Hello! We're using 2 keycloak instances. SP -> Keycloak (broker) -> Keycloak (Identity provider) How can we configure the broker to create user names equal to the original username from keycloak (Idp)? Now the new users inside the broker receive a G-.... (long meaningless string) username during the first log-in. So if user logs in through Idp with login: 'hello' we would like user 'hello' be created in the broker Thank you for advice.