Supported:
Shopify
Etsy
PayPal
eBay
Amazon
Stamps.com Web
Stamps.com Pro Software
Endicia Dazzle
ShipStation
ShipWorks
ShipGator
Shippo
ShipWire
ShippingEasy
UPS WorldShip
XPSship
EasyPost
OrderCup
FedEx Ship Manager
Poshmark
EasyShip
Label.live
ReadyShipper X