Make system hotkey appear brightness bar

When I change the sound, there is a volume bar, but I have never seen brightness bar when changing the screen brightness.
I've tried Acer Blue digit, but it does not show brightness bar either.

[irzyxa]

It will be shown only when you change brightness from Volume2 using hotkeys

Oh, I see that, after setting a hotkey for changing brightness, the brightness bar appears in some theme(e.g. windows 10 v2)
But pressing system default hotkey will not make brightness bar appear. Moreover, when I want to set system default hotkey as volume2 hotkey as well, this will lead to failure.
(but setting volume-up as hot key success beyond expectation.)