I cannot locate itunes app on my iphone

See if you hid it with restrictions:

Screen Time - Allowed apps https://support.apple.com/en-us/HT201304#allow-apps

- "If you turn off an app or feature, it won’t delete it, it’s just temporarily hidden from your Home screen."

- Settings > Screen Time > Content & Privacy Restrictions > [Enter passcode] > Allowed Apps

See if it is in your App Library -->

Organize the Home Screen and App Library on your iPhone [iOS14] - https://support.apple.com/HT211345

"Search for it ( https://support.apple.com/HT201285 ). Swipe down from the middle of any home screen and enter the app name into the search field at the top of the screen. If it is in a folder, it will show the folder on the right of the app name after you tap on the app when it appears in the search."