Keyboard Shortcut to control brightness


I am using Manjaro Xfce minimal version in my Acer laptop. Though I have a keyboard shortcut built-in in the laptop keyboard (one of those function keys) for increasing and decreasing brightness but I prefer using an external keyboard to use my laptop and it doesn’t have any media keys or any custom functional keys. So I would like to have a keybinding for controlling the brightness through my external keyboard. I tried using the xbacklight for that purpose but it doesn’t seem to work at all.