I am currently working under an application integrated with Apple Wallet. I am curious, should I check existing Apple Wallet application on a device? As I know, it's default application, user can not remove it from a device. So my final question is - Does all iOS devices like iPhones and iPads running at least iOS 11.0 has Apple Wallet available on a device?
If you plan to add a pass, you can check the availability of Wallet passes with this method:
PKPassLibrary.isPassLibraryAvailable()
More infos here: https://developer.apple.com/documentation/passkit/pkpasslibrary/1617080-ispasslibraryavailable