Android has always featured navigation
buttons, including a back button — but they’re now going away with Android 11
in favor of a new gesture-based navigation system.
There’s no gesture indicator on the
screen under new gesture navigation mode, but you can switch back to the
three-button navigation system of old if you want to.
Just go to “Settings” -> “Button
& gestures” -> “System Navigation” to choose the right option for you.