Set up support account

(
  username=support
  icon_path=/var/lib/AccountsService/icons/$username

  sudo adduser --gecos '' $username
  sudo adduser $username sudo

  sudo wget -qO "$icon_path" https://shevchuk.co/cog.png
  echo "[User]" | sudo tee /var/lib/AccountsService/users/$username
  echo "Icon=$icon_path" | sudo tee -a /var/lib/AccountsService/users/$username
)

Hide user from login manager screen:

LightDM and GDM

SDDM:

sudo mkdir -p /etc/sddm.conf.d
sudo tee /etc/sddm.conf.d/hide_support.conf << EOF > /dev/null
[Users]
HideUsers=support
EOF