Run custom tui menu on tty1 with systemd getty.

menu.sh

#!/bin/bash

set -e

function show_main_menu() {
  whiptail --nocancel --menu "Main Menu" 12 35 4 \
1 "Network Configuration" \
2 "Modify Hostname" \
3 "Factory Reset" \
3>&2 2>&1 1>&3
}

item=$(show_main_menu)
case $item in
1)
  nmtui edit eth0
  ;;
2)
  nmtui hostname
  ;;
3)
  echo "Factory Reset"
  read
  ;;
*)
  echo "QUIT"
  ;;
esac

override.conf

# /etc/systemd/system/getty\@tty1.service.d/override.conf
[Service]
ExecStart=
ExecStart=-/usr/sbin/agetty --autologin root --login-program /root/menu.sh --noissue --noclear %I $TERM

https://wiki.archlinux.org/index.php/Getty