Looking for Part Number (or Part)

[CONCH]

Hello - I recently installed the trailer wiring harness and have the short Tow Hitch Adapter. Seems the adaptor should fit in the left rear cubby. I found one on Amazon but it is for the "Swan Neck Adapter" style receiver, not the short version I have. Does anyone have a good Part Number for the proper cradle to hold my short style adaptor - or know where it can be purchased?
TIA