Welcome to the Auth0 Community!
It is possible to link user profiles automatically and here’s a link to our account linking documentation, however please review the disclaimer below before implementing your own solution:
Account linking is advantageous in many ways and can bring great benefits. Though
documentation, samples and guidance is available, current collateral is less than complete when it
comes to the security considerations surrounding account linking: the assumption is made that the
user who authenticated as part of login is the legitimate owner of any accounts to be linked. This
assumption opens up a potential security flaw which is described in the use cases below. Left
undressed this can have serious consequences, resulting in the potential for personal information
loss, denial of service or perhaps worse.
Feel free to reply with any follow up questions and I hope this helps!
Thanks,
Matt