In order to integrate CoreCommerce with ShipStation, login to your CoreCommerce account and from the Settings dropdown, click Plug-In Settings.
Now click ShipStation from the lefthand sidebar.
On the page that appears, toggle Enabled to Yes.
After the plugin is enabled, create and enter a username and password to connect CoreCommerce with ShipStation. Copy these along with the Script URL.
For reference, the status mappings and their ShipStation counterparts are shown below this section.
Once this is done, click Save and go to ShipStation.
Head to your Account Settings (the wrench icon in the upper right).
Next, select Selling Channels and then Store Setup from the sidebar on the left.
Click +Connect a Store or Marketplace.
Select CoreCommerce from the list of stores.
Then enter your Username, Password, and Script URL and click Connect.