How to check if my airpods pro are refurbished?

Apple does not sell refurbished AirPods.

Depends on where you bought them from. If you did not buy it from a apple store then you won’t be able to tell for sure, but maybe this will help

Check the AirPods Pro firmware

1. With the AirPods paired, charged, and out of the charging case
2. Go to Settings, General, About
3. Scroll down until you find the AirPods Pro listed
4. Tap on their name
5. Now look for Firmware Version

Again, you can tap and hold to actually copy that Firmware Version, but this time seeing it is enough. It will be a five-character number like 3E751.