Worked example
A seller with a GS1-assigned UPC-A 036000291452 can proof its barcode artwork here; a newly invented number with a correct check digit is not proof of ownership.
Before you print
Amazon listing identifiers and inventory labels serve different purposes. Confirm current listing and labeling rules in Seller Central for your category before production.
Barcode artwork is not proof of an assigned GS1 number. A free barcode image and a GS1-issued GTIN are different things.