Unity KeyCode for mute button for Fire TV remote - unity3d

Question

I have this problem when I'm looking at the amazon developer page for unity: https://developer.amazon.com/docs/fire-tv/controller-input-with-unity.html#controller-names
it shows the keycodes for all the buttons, except for the mute button on the remote.
My model is different; there's a volume button and a mute button. Neither of these are documented.
Thanks for your time!

Answer 1

Not a direct answer but you could maybe try to simply print it out using something like
public class Debug : MonoBehaviour
{
// Just print to a text so you can easily see the result on the screen
public Text text;
private void OnGUI()
{
var e = Event.current;
if (e.keyCode != KeyCode.None)
{
text.text = e.keyCode.ToString();
}
}
}
this way you could see which keycode responds to which pressed button/key etc.

Answer 2

According to the Fire TV Guidelines, volume +/- and mute are not to be mapped.
I heard that it's possible, but you will get rejected from the amazon appstore.
Source: https://developer.amazon.com/docs/fire-tv/remote-input.html
If you use the new input system, I released an asset on the assetstore which gives you access to all mappable buttons (Dpad, Select, Back, Menu, Rewind, Play/Pause, FastForward)
I'm not posting any links, but it's easy to find if you search for "Fire TV" on the asset store.