Once you have followed the steps in the 'PayPal Account Creation' section and have your PayPal account details, to enable PayPal Express:

1. In the admin console, go to Configuration > Site Setup Wizard.
   
   
2. In the Payment Methods section, click the configure link next to the PayPal Express Checkout entry.
   
   
3. Enter the values you obtained from PayPal for the API Username, API Password, and API Signature.
   
   
   
   
4. Enable the desired options and click Save and Close.


5. Finally, check the box next to PayPal Express Checkout and then click the Save button at the top or bottom of the page.

NOTE: The Integrated Checkout option is a lightbox overlay (your site is grayed-out behind it) allowing the customer to login and pay
through their PayPal account without appearing to leave the site.