iPhone Xs Max unresponsive

My iPhone XS Max has recently froze. It has been a little over an hour. I have tried to reset it, but holding down the upper volume and lock button will not work. I am not able to click on any apps, or when i click the lock button nothing happens. The screen gets very dim like it is going to shut off but just stays that way. All of my messages are coming through but i am not able to reply to any of them. What can i do?

[Re-Titled by Moderator]