When creating an inbound shipment plan, how do I add PrepDetails ?

https://docs.developer.amazonservices.com/en_US/fba_inbound/FBAInbound_Datatypes.html#InboundShipmentPlanRequestItem

I looked at the the source code in inbound_shipments.py and there is no reference to this parameter. We would like to set the PropOwner property when creating shipments

For example the request items would be like this:

&InboundShipmentPlanRequestItems.member.1.SellerSKU=SKU00001 &InboundShipmentPlanRequestItems.member.1.Quantity=1 &InboundShipmentPlanRequestItems.member.1.PrepDetailsList.member.1.PrepInstruction=Taping &InboundShipmentPlanRequestItems.member.1.PrepDetailsList.member.1.PrepOwner=AMAZON