How to set a folder name for each user on the server?

Question

Web development

For each user, when registering on the server (not on the one where the site is), a folder is created, but I can’t figure out how to name this folder, I don’t want to use the name and surname, because the user can change them, and this will have to contact the server every time and wait for his answer, I think it will take a long time, but I don’t know what to do.
You can by uid, but I want to hear more options

Answer 1

By uid