I can't find how to add additional information to the back of my card in Google Wallet. In Apple Wallet, in any case, this can be done and there are a lot of examples, but on Google I can’t even find an article with a description.
Those examples that exist are clearly not enough https://codelabs.developers.google.com/add-to-wallet-android#9
I am also interested in what file format should be used in the application to create a map. On Apple I use .pkpass for this.
I searched on the codelabs website and Google