Ubuntu uses GDM: https://wiki.archlinux.org/title/GDM
Ubuntu uses GDM: https://wiki.archlinux.org/title/GDM
Our company has this piece of software which has a lot of legacy shit. The installation process is complicated and it has a lot of loose batch, vbs and reg scripts which needs to be manually run. So someone from the company who made the software installs the software for us trough remote desktop connection. I always imagine that person to be a wizard.
Hide user from login list
The users for the gdm user list are gathered by AccountsService. It will automatically hide system users (UID < 1000). To hide ordinary users from the login list create or edit a file named after the user to hide in /var/lib/AccountsService/users/ to contain at least:
/var/lib/AccountsService/users/username
[User] SystemAccount=true