Wake the display: how to turn on the screen | iPadOS 14 Reference Guide

For iPhones with a notch:

Press the Side button or tap anywhere on the screen to wake the display. It will also automatically wake when you raise the iPhone to look at it.

For iPhones with a Home button:

Press the Side button or the Home button to wake the display. It will also automatically wake when you raise the device to look at it.