get
https://sellingpartnerapi-na.amazon.com/inbound/fba/2024-03-20/inboundPlans//shipments//contentUpdatePreviews
Retrieve a paginated list of shipment content update previews for a given shipment. The shipment content update preview is a summary of the requested shipment content changes along with the transportation cost implications of the change that can only be confirmed prior to the expiry date specified.