If the problem is affecting only one AirPod, you can force them to output audio.
If this doesn't work, you can also try disabling Bluetooth mouse. If you're using Bluetooth mice, they can interfere with your AirPods' connection.
To resolve this, simply turn off and on the wireless mouse and restart the AirPods. Once this is done, you'll be able to use your AirPods again.

We hope that these easy steps helped you in recovering your airpods and now you can enjoy music with both in ear. If your aipods have fallen in water or in any wet area, then you should check how you can throw water out of airpods without visiting any Apple Service Centre. Read here : https://cleanersuite.com/how-to-eject-water-from-iphone-airpods/