power off switch / accessing GPIOs

[TheOldPresbyope]

It looks like the GPIO Zero library isn't there since moOde is built on RaspiOS Lite.

Quoting from the GPIO Zero docs

Installation

GPIO Zero is installed by default in the Raspberry Pi OS desktop image, available from raspberrypi.org. To install on Raspberry Pi OS Lite or other operating systems, including for PCs using remote GPIO, see the Installing chapter.

Regards,
Kent