Summary: To successfully integrate ShipStation with Printful, log in to both ShipStation and Printful. You will move between both platforms to complete the connection. First, generate your API Key and Secret in ShipStation.
Step-by-step details to generate your API Key and Secret.
1. Go to your ShipStation Account Settings (the wrench icon in the upper right).
2. Select Account and then API Settings from the left-hand sidebar.
3. Click the Generate New API Keys button. Your API Key and Secret will now appear.
4. Copy these both (yours will look different from what's below) to paste into Printful:
5. Go to your Printful account and then go to the Stores tab.
6. Now find the Use ShipStation to connect to box and click Choose ShipStation.
7. You will be taken to a window where you can either scroll down or click on Connect as shown below. Click Connect.
8. On the page that appears, enter/paste your ShipStation API Key and Secret and click Connect.
9. Select the store whose orders will be imported, and click Connect.
Now the store will be connected!
Repeat this process for each store whose orders you want to have imported into ShipStation.