Before sending any request to Shipping 360 API, you will need to register for a Pitney Bowes account to receive an API token used for authentication.
For details refer here Quick Overview.
Authentication and identification to the API is done by providing a Bearer token received in response of Authorization /Token with every request.
Requests made without a proper Bearer token will fail with a 401 Unauthorized error.
curl --location 'https://api-sandbox.sendpro360.pitneybowes.com/auth/api/v1/token' \
--header 'Authorization: Basic MG9hMWx1czNlYnJCckNqUHIwaDg6ekdLRUNzcVhPekE0UEktdm42cm10UEhUeERNTVBFSTQzRnJEYlJpUg==' \
--header 'Content-Type: application/x-www-form-urlencoded' \
--data-urlencode 'grant_type=client_credentials' \
--data-urlencode 'scope=psapi'