Sorry that info. hasn't helped locate the missing AirPod : Did you: Set up and use Notify When Left Behind in the Find My app - Apple Support
If you didn't turn on Find My before your AirPods went missing, you can't use Find My to locate them: If Find My is offline or not working - Apple Support
Find My is the only way that you can track or locate a lost or missing device. There is no other Apple service that can find, track, or otherwise flag your device for you.
If you use iCloud, maybe try: iCloud+ - Find My - Apple or https://www.icloud.com/find
______________________________
AirPods Support Website:
Find all the topics, resources, and contact options you need for your AirPods...
AirPods Support - Official Apple Support
__________________
If needed: About Replacement : AirPods Replacement, Repair, & Service - Apple Support
More info: AirPods Express Replacement Service - Apple Support