Why can’t I delete an app from my App Library?

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How to delete apps on your iPhone, iPad, and iPod touch - Apple Support

you can delete from the App Library by locating the app and tap/hold, select Delete App

or you can go to Settings > General > iPhone Storage > [app name] > Delete

If you still are unable to delete, check:

Settings > Screen Time > Content & Privacy Restrictions > iTunes & App Store Purchases > Deleting Apps

make sure that's set to 'Allow'

Go to Settings/Screen Time/Content & Privacy Restrictions/iTunes & App Store Purchases - Change Deleting Apps to Allow.

Some built in Apple apps cannot be deleted. See: Delete built-in Apple apps from the Home screen on your iOS 14 or iPadOS device or Apple Watch - Apple Support

If no apps can be deleted, the usual reason is due to a restriction on deleting apps. See: Use parental controls on your child's iPhone, iPad, and iPod touch - Apple Support