Thank you for the answer.
But on the tutorial, it does not use the p2 connector of the Justboom AMP HAT.
But i see:
„For mounting on the Amp HAT, the pins need to be soldered a bit differently.The button needs to be soldered at (IR In) and (GND) of the U5 area.“
I will test connect button on U5 and I will tell you if it works.