You won’t be able to download Apps or make purchases from the App Store, if the App Store Icon is missing from your device.
The good news is that it is not possible for you or anyone with access to your device to accidentally or intentionally delete the App Store Icon from iPhone.
The reason for this is due to the App Store being an essential and built-in part of iOS, along with Apps like Safari, Camera and Settings App, which cannot be removed or deleted from iPhone.
Note: If you live in any Country within the European Union, the App Store can deleted and re-installed.
Restore Missing App Store Icon On iPhone
Since, the App Store is protected from being deleted, the reason for App Store Icon missing on your device is most likely due to that App Store being accidentally moved to a Folder.
Another reason for App Store Icon not showing up on iPhone is due to App downloads being accidentally or intentionally being restricted on your device.
1. Search For App Store
You can confirm that the App Store Icon is available on your device by searching for the missing App Store Icon on your iPhone.
1. Open the Search function on your iPhone – You can do this by tapping on the Search Icon on the Home Screen or tap on Settings and use the Search Bar as available on the Settings screen.
2. Type App Store in the Search Bar and it should bring up the App Store Icon in the Top Hit box or in Search Suggestions.
While this method confirms that the App Store is available on iPhone, it does not help in restoring the App Store Icon back to its usual location on the Home screen.
2. Reset Home Screen
Resetting the Home Screen Layout can help in restoring or bringing back the missing App Store Icon.
1. Go to Settings > General > Transfer or Reset iPhone > Reset.
2. On the slide up menu, select Reset Home Screen Layout option.

Once the Reset process is completed, you should find the App Store Icon back in its usual or default location on your device.
3. Disable Restrictions on App Store
If above methods did not help, it is likely that you may have accidentally placed restrictions on downloading of the Apps on your device.
1. Go to Settings > Screen Time > Content & Privacy Restrictions.
2. From the next screen, go to iTunes & App Store Purchases > tap on Installing Apps.

3. On Installing Apps screen, select the Allow option to enable Installing of Apps on your device.

After this, go back to the Home Screen and you should be able to find the missing App Store Icon back on your iPhone.