Apple is no longer signing iOS 14.7 and iPadOS 14.7 for iPhone and iPad users. You can no longer downgrade from 14.7.1 update.
iOS 14.7 and iPadOS 14.7 is No Longer Signed by Apple, iPhone and iPad Downgrades No Longer Possible
It was only yesterday we asked our readers to downgrade to iOS 14.7 or iPadOS 14.7 as Apple was still signing the older firmware. Today, all of that changes as the company has stopped signing said firmware. This means you have to stick with whatever you already have on your device or the latest iOS 14.7.1 and iPadOS 14.7.1 updates.
Given the security content of the latest updates, we will really not recommend downgrading or sticking around with older firmware at this point. If you want to update to the latest firmware over the air, then simply connect to Wi-Fi, navigate to Settings > General > Software Update. When the latest update shows up, tap on download and install.
Also keep one thing in mind, at this point there is absolutely nothing you can do in order to downgrade to any older firmware. Before a firmware is restored to an iPhone and iPad, the signing status is verified with Apple before it can be installed. So please, do not spend time installing the update over and over again in the hope for a miracle.