True.
Guess you have 2 options:
1: Create another table with userdetails that is not part of the User part of the database. For example a list of all usernames / first names taken. Obviously for every user register you need to create a new record
2: Create a custom thing under users. I’m not sure where this data is stored, but it’s stored somewhere (believe it’s directly related to the user because you will have add the userID