I have a registration page created using the Ultimate membership plugin, I don't want people to have to enter a username for registration. I tried hiding the username field and using some code, changing the display name to first name & last name.
However, since WordPress requires a username by default, it uses the user's email address as the username instead. For example this account (https://****nark.com/members/++++++gmail-com/)
I am wanting to automatically make the username = first_name-last_name . rand()