I don't have the serial number for the air pods

turn Bluetooth off, wait a few seconds, turn back on and try to pair them again. If that does not work:

Use this link https://getsupport.apple.com/?caller=psp&PGF=PGF32003 for Support and chose Find Your Serial Number.

here is how to find the serial number for your Air Pods:

Find the serial number of your AirPods

Your AirPods and your charging case share a serial number. Here's how to find it.

1. Go to Settings > Bluetooth.1
2. Find your AirPods in the list (for example, "John's AirPods"). 
3. Tap the info button  next to your AirPods, and you'll see the serial number.2

The serial number is also on the underside of the lid:

If you don't have your charging case, but you have the original packaging, you can find the serial number next to the barcode. You can also find the serial number on the original product receipt or invoice.

1. If your device is using a software version earlier than iOS 14 or iPadOS 14, you can find the serial number by going to Settings > General > About. Scroll down until you see the name of your AirPods, then tap the name.

2. With AirPods (2nd generation) and AirPods Pro, each AirPod also has its own serial number, printed on the AirPod itself. If you need to send your AirPods or charging case in for service, refer to the primary serial number, printed on the case lid. You don't need the serial numbers on the AirPods.