US Sellers Only:
Visit the link below to find out more about buying Amazon’s shipping services. Note: You must have an Amazon seller account to access the following link.
https://sellercentral.amazon.com/gp/help/200202220/ref=ag_200202220_cont_201526770
Canadian and US Sellers:
We recommend using ShipStation to manage your orders. You can integrate the major carriers and Amazon into your ShipStation account for easy management of orders. Try it for free for 2 months here: https://info.shipstation.com/altos-digital