Coupang runs a validity check on the waybill number to see if the same number has ever been registered over the recent six months.
If your upload fails with an error message like this even when you have entered a valid number, please use "DIRECT" as the courier code and proceed with the uploading.
For those waybills whose courier code is DIRECT,
Tracking is not supported. But there's nothing to worry about as their sales will be recognized on D+7.