How do I reset an unresponsive iPhone ?

I have a iPhone 14 pro max that was dropped and shattered the back of the phone as well as made the screen unresponsive. I received my new device and need to reset my old one. I tried to login to icloud to erase from there since the screen in unresponsive but upon doing so it said "iphone will be erased when put online" i am unable to get into my old device as the screen is unresponsive with the message that says iphone unavailable. How can i reset it????

[Re-Titled by Moderator]