To add a new user called snuk, use the useradd command:
# useradd -m -g users -G wheel,audio,video,seat,plugdev,netdev,power,input,lp,scanner snuk
Although it is not required to protect the newly created user snuk with a password, it is highly recommended to do so:
# passwd snuk
When lingering is enabled for a user, their user-level systemd instance stays active in the background, so timers, services, and background tasks can run without an active login session.
Let's lingering the new “snuk” user.
# loginctl enable-linger snuk