Amazon Shipping and OTDR through 3PL

I have products that are not viable if fulfilled using FBA. If I use a 3PL that specializes in this market segment, can I piggyback on the 3PL’s Amazon Shipping (the carrier) contract rates and still get OTDR protection? My initial thought is no, because the label has to go through Amazon Buy Shipping, which requires linking the carrier account to my Seller Central account.

Does anyone else use a 3PL and get OTDR protection from using the 3PL’s Amazon Shipping contract?