iPhone frozen with “accessory not supported” on screen

I plugged my phone into the charger & an accessory not supported screen popped up. I tried clicking okay, it’s frozen on the screen. Tried plugging in the phone again with multiple different chargers. Nothing is clickable on the screen, it’s now locked and I can’t power it off. I’ve also, attempted a hard shut off and it starts to make the iPhone’s emergency siren.