Create a new user. See also:
users
,userdel
,usermod
. More information: https://manned.org/useradd.
sudo useradd username
sudo useradd --uid id username
sudo useradd --shell path/to/shell username
sudo useradd --groups group1,group2,... username
sudo useradd --create-home username
sudo useradd --skel path/to/template_directory --create-home username
sudo useradd --system username