Is there has an error on the purchased on Appstore?
I already purchased the application on Appstore but I cannot install, or download the app.
iPhone SE, iOS 14
Question marked as
Check if you have a stable wifi/network connection.
Check if the App Store service is available. Apple - Support - System Status
If you have trouble downloading an app that's larger than 200 MB over cellular, open the Settings app. Tap App Store, tap App Downloads, then tap Always Allow.
If you can't still download it or isn't working as expected, you can contact the app developer. Or report a problem to Apple.