[keycloak-user] synchronize Users in old database with keycloak Database

Hi all, My question is about, how Can I synchronize my old database that contains users from another system with keycloak (kc). I'm trying to migrate my authentication software (legacy) to keycloak, but I'd like to keep the old users syncronized with the kc database. If I use Service Provider Interfaces (spi), I'll keep all users updated from keycloak info. But What about the reverse path? Is there a way to update keycloak with users from another database? Thank you. Best regards, Celso Agra