Register for a USPS User ID
Register for a USPS Web Tools user ID by filling out the USPS Web Tools registration form.
When you have completed the signup process, USPS will mail you a user ID. Make a note of this, as you will need your USPS user ID to complete the activation in Sweet.
Your USPS Web Tools user ID is a combination of letters and numbers, for example
123ABCDE1234, that is automatically generated by USPS.
The user ID will give you access to package tracking, rate, and service delivery standards APIs with USPS when you register.
Note: If you have any problems with your USPS setup, then contact USPS directly. Sweet cannot obtain your USPS credentials for you, nor provide support for your USPS account.
Activate calculated shipping for USPS
To activate calculated shipping for USPS:
Go to Configurations -> Carriers.
In the Carriers page, look for the USPS Settings section and enter your USPS credentials.