Unity NativeActivity how to response BackKey in Android onKeyDown()

My code use Unity Android Project。and i found Android onKeyDown function can’t response,
i change AndroidManifest.xml

but only response by Unity

       void Update ()
    {
        if(Input.GetKey(KeyCode.Escape)){
            Debug.Log(" Back Key");
        }
    }

can’t response on Android onKeyDown function, how to do it?

Yes i have the same problem… i will follow this thread.

I just checked my code and here’s what I’m using that works…

if(Input.GetKeyUp("escape"))