iPhone 12 screen not responding

I have searched and searched for an answer to this. My wife’s iPhone 12 will not respond at all. The camera button is greyed out and I have forced reset it 20 times using the volume and lock buttons. Nothing. All I can gather is that it needs to be updated but I can’t get into the phone to update it!!! It’s driving me mad.

let me guess there’s no solution to this yet??

I have even plugged it into a MacBook and even then I can’t do anything as I need to unlock the phone for it to communicate with the MacBook!!!!