Pairing airpods

Is it possible to pair two separate apple AirPods. My partner dropped his left into a pot of paint and my nephew lost his right down a drain. I’ve tried making one good pair but cannot get them to work together. I have followed various instructions from different sites but the charging box keeps flashing Amber regardless. One site says I need to buy one new AirPod direct from Apple using the original AirPod serial number. Is this right? Both are 2nd generation. Any help appreciated.