iphone won’t update

The iOS 14 BETA that you downloaded is the same version as the iOS 14 release version. This is why you do not see an option to update to the release version. Note that the current iOS 14 BETA version is 14.2.

Since you are no longer interested in BETA testing, I recommend that you remove the Beta Profile form the iPhone so that you can remain current with the release versions of iOS. To remove the BETA profile from your iPhone:-

To delete the profile, Open Settings ➔ General ➔ Profiles : Here you will see the iOS 13 Profile to delete.

Axel F.

Remove the public beta by deleting the beta profile

Go to Settings > General, and tap Profiles & Device Management. Tap the iOS Beta Software Profile. Tap Remove Profile, then restart your device.

How to uninstall iOS beta software - Apple Support

Then --> Update your iPhone, iPad, or iPod touch - Apple Support