You need that text field because the hack relies on pasting text into that field to crash the lock screen. You can see in the video below how the hack works.

Furthermore, the hack was initially discovered on a Pixel phone, but the bug lives in the code available in the Android Open Source Project (AOSP).

Your Android phone may seem entirely secure when it’s locked, but that’s not necessarily true. Unless you adjust the right settings, the lock screen can allow access to messages, controls, and ...