DDU payment Incoterms (or Delivery Duty Unpaid) means the receiver/customer will get contacted by customs once their shipment arrives, and will have to settle any charges in order for customs to release the shipment and have it delivered to the customer.
DDP (Delivery Duty Paid), on the other hand, means the seller assumes all responsibilities and costs for delivering the goods to the named place of destination including both export and import formalities, fees, duties, and taxes.