How can I open my expo app in XCode in order to enable Apple Pay

I’m trying to integrate Apple Pay with my Expo app, and I found these instructions here.

open the application in XCode and navigate to the capabilities tab. Enable Apple Pay and insert your merchant ID into the corresponding space.

I was able to successfully set up my Apple Merchant ID, but I’m not really sure how I should be “opening the application in XCode”. Any help would be appreciated here - thanks