How to Setup USPS Shipping Method in Magento 2. The USPS Carrier allows you to offer the domestic and international shipping services on ground or airway conveniently. This is the service of United States government and is famous for it’s flat rate shipping for smaller size and lightweight items. Their USPS Priority service is one of the most popular eCommerce shipping methods in Magento because it is flexible.
Thus, what credentials you need to connect your Magento 2 store to the USPS serve.