[keycloak-user] Replace username with phone number

Hi Everyone, I am new to Keycloak and I am considering using it in a project. However I've been playing with Keycloak for a bit and cannot seem to find out a specific need for the project. The need is to signup and make the phone number of a user to be the user identified instead of the username. What I did was: created an empty realm, exported it, then modified the properties using username to be phonenumber, and imported it again. Then created a new theme based on the basic theme and changed username to be phonenumber. But it wasn't enough and in the UI there was a lot of reference to username. So I was wondering if this is possible or not, and if possible how can I achieve it? Thanks in advance. -- Regards, Ahmed Ossama