Control Center: how to open Control Center from anywhere | iOS 14 Reference Guide

For iPhones with a notch:

Swipe down from the top right corner of the screen to reveal Control Center. If you’re in a full-screen app, you may need to swipe twice.

For iPhones with a Home button:

Swipe up from the bottom of the screen to reveal Control Center. If you’re in a full-screen app, you may need to swipe twice.