Setting up Wallet App
I do not see a Wallet app or an Apple Pay app to add to my App Icons.
iPhone X
Question marked as
Apple Pay is a service and does not have an App. Credit and debit cards are added to Apple Wallet app. Wallet app comes on all compatible Apple devices. If you removed Apple Wallet app, you can download it for free from the Apple App Store.
Follow the steps in this support article for adding credit/debit cards to your Wallet.
Set up Apple Pay - Apple Support
Make purchases using Apple Pay - Apple Support