AirPods not working

It's hard to find out the problem without anymore description but here are some articles that might help.

If your AirPods won't connect – Apple Support (UK)

How to reset your AirPods and AirPods Pro – Apple Support (UK)

If your left or right AirPod isn't working - Apple Support

In this case try resetting your AirPods.

1. Put your AirPods in their charging case and close the lid.
2. Wait 30 seconds.
3. Open the lid of your charging case, and put your AirPods in your ears.
4. Go to Settings > Bluetooth. Or go to Settings > [your AirPods].

• • If your AirPods appear there as connected, tap the More Info button  next to your AirPods, tap Forget This Device, then tap again to confirm.
  • If your AirPods don't appear there, continue to the next step. 

1. Put your AirPods in their charging case, and keep the lid open. 
2. Press and hold the setup button on the back of the case for about 15 seconds, until the status light on the front of the case flashes amber, then white.*

How to reset your AirPods and AirPods Pro – Apple Support (UK)How to reset your AirPods and AirPods Pro – Apple Support (UK)