I lost my left airpod can I buy it?

Yes. See the following from How to find your lost AirPods, AirPods Pro, or AirPods Max - Apple Support

If you still can't find your AirPod or Charging Case, or if something is damaged, get the serial number and then contact Apple Support for a replacement. Then learn how to set up your replacement.

You can also learn more about AirPods pricing and service options.

Hi there! Refer to this link...

https://discussions.apple.com/thread/252352916?answerId=252352916021#252352916021