Hiding a specific user from the User Accounts GUI

[Ralf Mardorf]

Hi,

I don't know what display manager is used by default.

https://www.startpage.com/do/search

   lightdm hide account from login screen

First hit:
https://askubuntu.com/questions/92349/how-do-i-hide-a-particular-user-from-the-login-screen

Regarding a German Wiki, my guess seems to be correct
( https://wiki.ubuntuusers.de/Displaymanager/ ), anyway, just in case.

https://www.startpage.com/do/search

   gdm hide account from login screen

The third hit might not be exactly what you want, but assuming you read
other instructions for GDM, take care that that they are for the
version of GNOME used by Ubuntu:
https://help.gnome.org/admin/system-admin-guide/stable/login-userlist-disable.html.en

Regards,
Ralf