The API responds by sending purchase order details in the response:
Order number in
E020: "%s" Invalid Order Item ID
E021: OMS Api Error Occurred
E023: "%s" Invalid Order Item IDs
E025: "%s" Invalid Shipping Provider
E026: "%s" Invalid Tracking Number
E029: Order items must be from the same order
E031: Tracking ID incorrect. Example tracking ID: "%s"
E073: All order items must have status Pending or Ready To Ship. (%s)
E063: The tracking code %s has already been used
E091: You are not allowed to set the shipment provider and tracking number and the delivery type is wrong. Please use send_to_warehouse
E119: Some order items are not yet ready to be processed, please try again later. (%s).
One or more order items are not fully handled by Seller Center, so they cannot be processed yet.
E121: Invalid Packing ID