I am trying to test the CompleteSale Trading API call, by setting the ShipmentTrackingNumber and ShippingCarrierUser fields. The call fails when I include the ShippingCarrierUsed parameter with the following message. "You have entered an incorrect shipment tracking number/carrier."
I am guessing the reason behind this is that the order I am trying to complete already has a tracking number associated with it. I am using the automated sandbox account 'external_api_seller'.
After reading the documentation of how to test CompleteSale (https://developer.ebay.com/DevZone/XML/docs/Reference/ebay/CompleteSale.html) it says I need at least two users. This is where the trouble starts. I can not login to the sandbox with a second user (or any user for that matter).
I can not reset the sandbox user passwords, I can not login with any of my sandbox users. How can I properly setup my sandbox environment to test the CompleteSale API call?