Log in to your account on the Designer server then click on the "Accounts" link in the left menu bar. The Designer server will display the API data that you need to copy and paste into the Magento system:

In the Magento admin page, navigate to System/Configuration. In the left menu bar, select Catalog/Catalog. Find "Product Personalization" and configure:
- API Username
- API Key
- API Version. Use: 4.0.0
- URL for the Designer server. The URL should terminate in "/".
- API Image URL. Leave blank
- Window type. Select "Modal pop-up" to open Designer inside modal pop-up durectly in the Magento site.
- Background color of modal pop-up. Do not prefix color with "#".
- Modal window opacity. Set opacity in range 0%-100%. Opacity should terminate with "%"
- Margin around modal pop-up. Size of margin between full size of window and modal pop-up. Do not terminate with "px".
- Designer extension loads jquery: If your Magento theme loads jquery, set to "No".
The Key and the URL are available from your control panel on the
Designer server. Please login to retrieve these.