frozen iphone 11 pro max

About an hour ago my phone started to slow down and wouldn't load instagram so I closed out of the app, did the swipe up thing to really close instagram, and then reopened the app but it got stuck on the white page with the logo and wouldn't load. It's now been an hour and my phone is still on the instagram white screen, is started to heat up, I can't power off or restart my phone. The only thing that works is when the screen goes black, I can turn it on, use facial recognition but I still can't leave out of the instagram app. Does anyone know how to fix this?