After the customer loads the goods for shipment, ask the customer for the bill of lading/invoice/packing list.
When the goods arrive at the port (the freight forwarder will call to inform your company), provide a customs declaration power of attorney to make an import declaration (you can entrust the freight forwarder to do), plus the bill of lading/invoice/packing list can be.
Don't book the ship notice, the customer booked the ship.