You will need to contact USPS and ask for permission to use this API.
Articles in this section
- How do l add the USPS tracking code to the Order?
- Pay for Shipment?
- You can create a label for these services.
- Error for Package 0 : XML Syntax Error: Please check the XML request to see if it can be parsed.
- A list of the USPS API's that you will need Permission to use.
- Error for package 0: API Authorization Failure. User __________is not authorized to use API Delivery Confirmation V4
- Error for package 0: can't open file