If the phone always shows "No Command" or randomly restarts to that screen, your . A stuck button sends constant signals that interrupt the boot sequence. Try cleaning around the buttons with a toothpick or compressed air. If that fails, a repair shop may need to replace the button flex cable.
LG devices are notorious for varying button sequences based on the software version. If the Power + Volume Up tap fails, try: hard reset lg k9 no command
If you see the "fallen Android" icon with the "No Command" text: Hold the Power button While holding Power, tap the Volume Up button once Release both buttons simultaneously If the phone always shows "No Command" or