There is an error that says 'Please check [Courier code]'.

First, please check if you have entered Y for remote area delivery.( remoteAreaDeliverable = "Y" )

Only the courier companies registered to the place of shipping can be entered in the remote area delivery.

(If you do not input Y for remote area delivery, you can select any courier)

Please choose the courier registered to place of shipment by checking place of shipping.