If you're wondering how to restore the App Store on your iPhone, there are several ways to install and reinstall apps that you purchased with your Apple ID. To begin, open the Settings app and tap iTunes & App Store. Make sure it says Allow next to Install Apps, Delete Apps, and In-app Purchases. If one of these options says Don't Allow, tap it, and then tap Allow.
You can't delete the App Store. If you're on a different home screen, have placed it in a folder, or have restrictions turned on and have hidden it, you can find it by going to Settings, then General, and then Restrictions. When you've returned the app to the home screen, note its location and your phone's restrictions to ensure easy access to your App Store in the future. You can also modify settings for automatic downloads of music, apps, books, audiobooks, and updates by opening Settings, tapping iTunes & App Store, and enabling the corresponding options using the slider buttons provided. The options you can choose from include automatically checking for application updates, downloading new updates in the background, installing application and macOS updates, and downloading previously purchased programs on other Macs with the same ID. Mac users can locate and review previously purchased App Store programs by opening the App Store, for which an icon appears in the Dock by default. You can also confirm that you're signed in with the Apple ID that you used earlier to purchase the software and, with the App Store open, tap Search and then type the name of the application you want to install. These steps can also be used for other missing or deleted applications.
Here's how to add an app back to the home screen: open up the App Store and search for the app. Tap on it when it appears in search results. Tap on Get, then tap on Install. Enter your Apple ID password if prompted.
The app will begin downloading onto your device. The App Store can't be deleted, so it's just a matter of figuring out why the App Store icon is missing. With these steps, you should be able to restore your App Store icon and access all of your previously purchased apps.