Amazon Marketplace Web Service (MWS) will no longer be available after December 31, 2023. All MWS developers must migrate to Selling Partner API (SP-API) to avoid service disruptions. Refer to the Migration Hub for more information.
Step 5 - Use an Amazon-partnered carrier for your inbound shipments (optional)
Sellers in the EU region (the France, Germany, Italy, Spain, and UK marketplaces) and the US
marketplace can take advantage of discounted shipping rates by using an Amazon-partnered
carrier for their inbound shipments.