I cannot update to iOS 14.7 it’s say unable to verify update

iOS 14.7 is no longer available. Until iOS 15 is released you get 14.8. You may wish to restart your update because it is possible your device is confused.

About the security content of iOS 14.8 and iPadOS 14.8 - Apple Support

Check here:

If your iPhone, iPad or iPod touch won’t update - Apple Official Support

Check the iPhone for a beta profile.

Remove the profile, and check again for an update.

NOTE: iOS 15 will be releasing soon.