New at this site, and just starting to try nopcommerce. I got the codes and test server for UPS and USPS (USA). It works for showing shipping cost with UPS, but when I add USPS I get this message :
USPS Error returned: Error Desc: API Authorization failure. RateV4 is not a valid API name for this protocol.
What have I done wrong here ??
Also - how can I print the shipping label, and of corse pay for the postage in nopcommerce ??