How do I turn on automatic updates for iOS?

iOS 12 lets you update your iPhone's operating system automatically, how do I do it?

With iOS 12, you can now have your iPhone or iPad's iOS automatically update, just like your apps. Head to Settings -> General -> Software Update -> Automatic Updates and toggle it on. While it is on, your iPhone or iPad will update overnight provided it is charging and connected to Wi-Fi.

How to turn on automatic updates for iOS on iPhone and iPad.