iPhone shortcut to shutdown

I want a shortcut to shutdown my phone everyday at 20:00 without the confirmation prompt, and when the phone is locked. The 'Shutdown' action in Shortcuts seems to have the confirmation prompt built in by default and therefore doesn't work for me. Is there any other way, perhaps with some custom script?

This is for my organisation's phones used only with card readers for payments (needing to be mobile) but people forget to switch them off at the end of the day so the battery is drained when we need to go out on site again next day, making it a huge help to have this facility.