How to get Apple Wallet icon on my iPhone?

The Wallet app is pre-installed.

Look for this icon:

If you somehow removed it, it can be redownloaded from the App Store app.

https://apps.apple.com/us/app/apple-wallet/id1160481993

Otherwise, look for it in other home screens, in folders or in the App Library.

click here ➜ Organize the Home Screen and App Library on your iPhone - Apple Support

You will need to download the Wallet app (if available in your country’s App Store) and the icon for the Wallet app will be on your iPhone.