How do I fix it
How do you fix your airpods when they only play in one ear
Question marked as
Apple support has articles online (links below) that may help:
Learn what to do: If your left or right AirPod isn't working - Apple Support
Else: You might want to check the volume level on the AirPods themselves:
Pause, skip, and adjust volume with your AirPods and AirPods Pro - Apple Support
Make sure nothing (a speck of dirt or wax) is blocking the microphone and speaker
How to clean your AirPods, AirPods Pro, AirPods Max, and EarPods - Apple Support
If you have with AirPods Pro ... try Headphone Accommodations :
How to: Customize headphone audio levels on your iPhone or iPad - Apple Support