Previously all USPS APV disputes had to be filed either by email or by phone with USPS. They finally modernized the process with an online form, effective yesterday, Oct 23, 2024.
Here's the USPS industry alert that outlines the process with screenshots:
https://postalpro.usps.com/node/13550
Here's the actual webform where you can submit your dispute:
https://apvdisputes.usps.com
I'm editing this post to include a link to the eBay labels page where you can find info on any USPS APV adjustments applied to your eBay labels:
https://www.ebay.com/ship/lmng
