Overview

Configuring PayPal PAyments using the "Express Checkout" integration.

Configuring Express Checkout

Click on PayPal under Methods and it will go to this screen make sure that Paypal Express Checkout is selected in the dropdown box. 

Advanced Settings

Click on the Advanced tab on the far right side of the page for more options:

The page will then expand to give you a more configuration options.
In the advanced section you'll choose "Live" from the "Environment" drop down menu, the rest of the advanced configuration section are optional. 

Once you've made your selections make sure the click the orange Save button before leaving the page.