how do i create digital card which we can download from website?(e.g stored)

[phpdeveloper1984]

I want to create a downloadable digital membership card(e.g card which we use at store after purchasing but these are physical cards. i am talking about digital cards or e-cards) for my custom based php framework.

I have created one functionality where they have to login to access the virtual card but i want to create one functionality to download that card and save it on phone to use it as digital card on store to purchase

what would be the best approach ?

Is APIs for passbook (for apple) and passWallet (for android) is best approach? I am using custom php framework.