Keep Proxmox running normally
Turn off only the laptop screen/backlight
Prevent suspend/sleep on lid close
nano /etc/systemd/logind.conf
#add
HandleLidSwitch=ignore
HandleLidSwitchDocked=ignore
HandleSuspendKey=ignore
HandleHibernateKey=ignore
systemctl restart systemd-logind- Turn off the laptop display only
apt update
apt install vbetool
vbetool dpms off
vbetool dpms on