The GetPackageLabels, GetUniquePackageLabels, GetPalletLabels, and GetBillOfLading operations return PDF document data
for printing shipping labels and carrier labels for an inbound shipment. Amazon
compresses PDF document data before returning it as a Base64-encoded string. To
obtain the actual PDF document, you must decode the Base64-encoded string, save
it as a binary file with a “.zip” extension, and then extract the PDF file from
the ZIP file. These operations also return a Base64-encoded MD5 hash to validate
the document data.