If you are doing a screen recording, you can click on the red clock at the top to stop it.
Stop a screen recording from the status bar
NEXT TIP
How to Record a video with music playing
You can record a video with music playing by opening the camera, holding the photo button, and swiping to the right.
TIP FROM
10 iPhone Tips and Tricks for Screenshots, FaceTime, and More
Useful iPhone tips including screen recording shortcuts, screenshot editing, keyboard tricks, and ambient sounds