Manually create user

[lakhai]

hi!
I'm trying to connect my wordpress users with the vB forum, what I want is when a user is created on the WP site to automatically create a forum user with the same login, email and password.
I was using the method from this ancient thread: https://vborg.vbsupport.ru/showthread.php?t=82836
which seemed to work when creating the user, but I cannot set the password as I get the "Field password is not defined in validfields in class..." error.
I then looked at the validfields array in vb/datamanager/user.php field and couldn't find a password field, of course. The closest thing I could think of was the 'secret' field, but that is set as not required and though it creates the user without errors I can't login because of the "invalid_password_scheme" error on login.
What is the best way to create a user via PHP?
Thanks in advance, cheers!