I’d be very surprised if repairs on AirPods circuitry were possible or cost effective. Just swapping the battery requires basically soldering iron surgery and permanent damage/removal of all adhesive that keeps it together.
You'd be surprised what they can do in Vietnam. Airpods are assembled there. If you have a local connection, You can find people who have worked in the factories.
Beyond that, the whole culture is to repair things because there isn't an official Apple store. They can also import parts from China and elsewhere.
Here is pricing to get parts from Singapore... most expensive repair is $100...
https://www.ifixit.com/Guide/AirPods+Pro+Battery+Replacement...