[keycloak-user] How to migrate passwords

Hi, I am trying to follow chapter 11.9 in server development to migrate users from existing database to Keycloak. I've implemented UserStorageProvider and CredentialInputValidator and unlinked the user in isValid method. However I am not sure, how to transfer the credential to keycloak. In our local database we have only hashes, so the only moment we have access to the password is again only in isValid. Is this the right method to transfer password and how do I set it on the UserModel? Regards, Robert Smol