If you already see the Screen Recording icon in Control Center, you can skip this part.

Since phone calls and notifications can also be recorded with screen recording, you may want to enable Do Not Disturb before continuing. To enable DND, open Control Center, then tap the moon crescent icon that represents Focus. From there, select Do Not Disturb. [1] X Research source

To also record sound, press and hold the screen recording icon in Control Center and tap the Microphone Off/On button. It’ll turn red to indicate that the microphone is recording; a grey icon indicates that the feature is off. When the screen recording is on, you’ll see the time stamp in the upper left corner highlighted in red.

You’ll find your screen recording in the Photos app. [2] X Research source

You’ll find your screen recording in the Photos app. [2] X Research source