Last few weeks I got 2 notifications of some of my shipments - Shipment problem to resolve - Missing tracking information (less than truckload/full truckload shipments).

Both shipments were sent from 3PL to FBA by Amazon Partner Program by Pallets. I did it many times before and never was asking to provide extra tracking Information. In explanation to this shipment problem it's said: For less-than-truckload and full-truckload shipments, one progressive freight number (PRO) is required for each shipment. To avoid this problem in the future, ensure that you provide tracking information before your shipment enters Receiving status.

I have a copy of signed BOLs for both shipments. There're PRO numbers but I have no idea that we're required to add this PRO number to shipment details in seller central. I couldn't find a place where to add it even. Please advise if somebody experiences similar "Shipment problem to resolve"? Did I miss something from Amazon regarding adding PRO number there? Where exactly do I need to add it?

Thank you!