Your unit should be in its original condition with the included chargers and must be packaged inside an outer unmarked shipping box. Please remove ALL of the original labels/stickers on the outside of the box before printing/attaching the return label then drop it off at any FedEx location. If you do not have the original shipping box, any generic box will work just as well.
Jackery is not liable if your package is damaged or lost due to mislabeling or improper packaging before it is dropped off at the FedEx facility.