Step 1: Enable Shipstation in pref_warehouses. Only developers have access to do this.
Step 2: Enter the SS API keys
In the WMS go to System Config – Preferences – Operations tab
Step 3: Map all shipping methods used by ShipStation into Shipedge
Go to the shipping methods table under the shipping tab in the OMS. Enter the Shipstation code for the relevant shipping method into the LS-Code field.