Pirate Ship is great if you want USPS labels up to 87% off and straightforward...

https://bizzmarkblog.com/pirate-ship-vs-shippo-for-beginners-which-is-less-confusing/

Pirate Ship is great if you want USPS labels up to 87% off and straightforward phone support. It’s perfect for sellers who ship mostly USPS. But if you need DHL Express or prefer email-only support, Shippo might be a better fit