You can check the current status of a shipment sent with a return code using the Report function.
The status will be in the <reverseReturnPackStatus>Sent</reverseReturnPackStatus> parameter.
The parameter will be returned when a shipment is sent using the return code.
Using the shipment number that will be available in the <reverseReturnPackCode>600000627283000026230130</reverseReturnPackCode> parameter, you can check the status of shipments using the ShipX API.