Can lost AirPods be replaced?

See the following from Find your lost AirPods - 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.

My wife dropped one earbud in the toilet and flushed by accident. Can I purchase a single replacement?

i lost my AirPods out of the case and find my iPhone won’t work