Hello Lea_codreanu,
Thank you for reaching out to Apple Support Communities, and we'll be happy to help in any way we can. We understand you're having issues with the volume of your AirPods. Try the steps here to see if they resolve the issue: If your left or right AirPod isn't working - Apple Support
"If there's low volume in one AirPod
If your left or right AirPod isn't playing any sound, or if the volume is too quiet, follow these steps:
- Check the microphone and speaker mesh on each AirPod.

- If you see any debris, clean your AirPods using the guidelines in this article, and see if that fixes the issue.
- Go to Settings > Accessibility > Audio/Visual > Balance, and make sure that the balance is set in the middle."
If the issue persists, try the reset here to resolve the issue: How to reset your AirPods and AirPods Pro - Apple Support
We hope this helps.
Cheers!