Apple Pay Not Appearing in iMessage

I am running iOS 11.1 on an iPhone 6, and want to set up Apple Pay in my iMessage app (wallet and Apple Pay are already set up). I am unable to see the Apple Pay app in the App Drawer, though. I do have Restrictions turned on for in-app purchases and wanted to know if this was the issue or if there is another reason that Apple Pay is not appearing in the App Drawer.