OpenWrt on APU2C4 how to attach functions to a push button?

Hardware Questions and Recommendations
#1

How to config hardware button? In LuCi Web its absent. I want tp toggle WiFi with it.

#2

Install the APU2 GPIO package -- and a switch too, I think. I don't recall any of mine being easily accessible outside of the case

#3

Thanks for an answer. This packages installed. Try to dig deeper.