Hello and welcome to Apple Support Communities, kuotyy!
We understand the Wallet app has been removed from your Home Screen and you're only able to access it from the App Store. We'd be happy to provide information on how to get the icon back to your Home Screen.
On your iPhone, swipe all the way to the right. You should see the App Library. If you don't see it, follow the steps here:
Organize the Home Screen and App Library on your iPhone
Once there, find the folder named "Utilities" and tap on the section of that square that shows a smaller group of apps, otherwise the app you tap on will open. You can skip that last step if Wallet shows up already. Once you locate the wallet app, press and hold on it and you should see the option to "Add to Home Screen". You can also hold the app and once it begins to jiggle, drag it to your Home Screen.
Let us know the results.
Have a great day!