https://wccftech.com/iphone-might-soon-get-over-the-air-os-recovery-as-per-ios-13-4-beta-code/

Apple may be working on an over-the-air OS recovery feature for iPhones, as per code found in the latest iOS 13.4 beta. This feature will allow users to restore the operating system on their iPhone, without connecting it to a computer using a cable.

The code was found in iOS 13.4 beta 3 by folks over at 9to5Mac. A pop-up, similar to the AirPods connectivity pop-up, is available in the beta, which simply says 'OS Recovery' and features a connect button. The existence of this pop-up suggests that Apple might allow users to restore the operating system on iPhone, and perhaps iPad and iPod touch, without connecting the device to a Mac or Windows PC via a cable.