Hi there,
It is possible to hide applications from the Home Screen if your iPhone is running on iOS 14 or later. If you have hidden any apps from the Home Screen, they will always be accessible through the App Library. Below is a link which details how to organize the Home Screen and App Library on your iPhone:
https://support.apple.com/en-us/HT211345
When you find the app in the App Library, you can hold down on the icon for additional options. If it is not currently visible on the Home Screen, one of the first few options will say Add to Home Screen. Simply tap that, and the app is back!
Cheers!