How to use Walmart savings catcher with Walmart grocery pickup

Update: This is no longer available. I am totally bummed that they no longer allow you to use the savings catcher with grocery pick up. If you want to send a POLITE email to Walmart customer service asking them to bring it back you can here.

I love Walmart Grocery Pickup. It's a busy mom's dream! But how do you use it with the savings catcher program? 

If you don't know what savings catcher is it's a program that compares Walmart's prices to the advertised prices of competitors. It puts the difference on a Walmart gift card for you. So how do you use that with grocery pick up?