Connecting Wordpress Users database to custom databases auth0

HI i am using wordpress with memberpress. all my users are created in wordpress user table. i am using a custom signup form. i want to synch users to auth0 custom database . when a user signed up using signup form in wordpress the user need to automatically sych to auth0 database. i try to create a database and connect to users in wordpress i am getting this error - “data and hash arguments required” . what is the best way to do this. i need help connecting users. without using auth0 signup form.
Thanks in advance