We are building an application for one of our clients in which I want to add your USPS Shipping API but I am facing some obstacles there. I can do my authorization. I can create Address Validation and Carrier Pickup using that Authorization token, the problem is when I go to create Domestic Label. X-Payment-Authorization-Token or Payment Payment Authorization Token is required to create Domestic Labe. For which we This is https://api.usps.com/payments/v3/payment-authorization Make a post request call to the API using the authorization token. Then I get an error Unauthorized
Why I am not getting Payment Authorization Token Please let us know which step I am doing wrong.