How do I turn off do not disturb

Swipe down from the top, right corner of the iPhone and you should get your "Control Center" screen. "Do Not Disturb" should be highlighted if it's on. Tap it to turn it off.

However, your system may have been trying to "learn" from your habits, and is turning it on to anticipate your decisions. If this is the case, go to:

Settings

Focus

Go through each of your existing "Focus" groups. After tapping on one of them, scroll until you see "Smart Activation". Turn it OFF. If there is an active SCHEDULE (right below "Smart Activation"), delete it by tapping it, and scrolling to the bottom and selecting, "Delete Schedule".

This should help!