I lost my airpods pro case and don't have the original packaging. How can I find the serial number?

To find the serial number without the case put the airpods in your ear (hopefully they have enough charge) and then go to iPhone SETTINGS, GENERAL, scroll down until you see your AirPods Pro, and touch that and voila.

Because it keeps asking your for the serial number when you try to order the replacement case, that's why. To find the serial number without the case put the airpods in your ear (hopefully they have enough charge) and then go to iPhone SETTINGS, GENERAL, scroll down until you see your AirPods Pro, and touch that and voila.

not sure what you think you need the serial number for

https://support.apple.com/airpods/repair/service

if you scroll down to Damaged AirPods you can see the prices for the replacements

You can see pricing there, but you need the serial number to actually order or even get a chat started with support to get help.

I lost my AirPod pro’s case how can you help me?