Although the package and order was delivered by a non Amazon carrier ( not USPS, UPS.. ) , the buyer is not seeing the order in delivered status. It is showing Running late in the buyers account.
I tried to look up various other SP-API operations to check if seller/shipper can set the shipment tracking status to Delivered but could not find any.
For example - Feeds API Order Fulfillment Feed also does not seem useful. Also POST /vendor/directFulfillment/shipping/v1/shipmentStatusUpdates seems to be for Vendor Shipments and not Seller Shipments. https://spapi.cyou/zh/references/vendorDirectFulfillmentShippingV1.html#%E6%8F%90%E4%BA%A4%E5%8F%91%E8%B4%A7%E7%A1%AE%E8%AE%A4
The seller/shipper used operation updateShipmentStatus SP-API to confirm shipment of order and is showing Shipped since 10 days in seller central. The carrier was a non amazon carrier and and tracking id was updated without a URL of the carrier. https://developer-docs.amazon.com/sp-api/docs/orders-api-v0-reference#updateshipmentstatusrequest
For operation updateShipmentStatus the enumeration of the field Shipment Status also just contains ReadyforPickup, Pickedup or RefusedPickup https://developer-docs.amazon.com/sp-api/docs/orders-api-v0-reference#shipmentstatus and does not allow us to update shipment to delivered.
Although the item is delivered, we do not want the customer/consignee to be able to request for refund just because they keep seeing this order as late on Amazon.
We want a way to logically complete the process and mark the order as Delivered using SP-API.
On a separate note - For another order the shipper has also tried to send the full URL of the carrier tracking site in the tracking number field. However it is observed that the order shipped email notification was not sent by Amazon in this case.