For warranty registration, if you purchased from avantree.com OR AvantreeDirect Store on Amazon / Walmart etc, you only need to provide the order number.
If you purchaesd from other stores, you will be asked to provide Proof of Purchase. You can simply provide the screeshoot or photo image of the order. Please make sure that the image contains the Store/Seller Name, Order No., and Purchase Date.
Please use the examples below (Amazon, Walmart, Lazada, Aliexpress, Newegg, Offline Outlet, Other Online Outlet) as reference: