If I lose my AirPods can I get a replacement?

I was at this fair in which my AirPods got lost on a ride. I didint realise they were lost until after the fair. I’ve searched on find my and only seen no location found. Today the AirPods don’t even show up on find my. So I have a feeling they are long gone. I saw on apple about lost AirPods you can get a replacement on lost AirPods if you have the airpod serial number. If this is true how do I do this?