[LE] add button icon in tutorial message

[AlimAge]

I created my own tutorial message that asks me to press a button (in this case left alt).
I searched the Internet and found a site that provides tags for displaying a specific key that corresponds to its action. For example [Activate] means E and so on.

The fact is that I have an action from the mod assigned to Alt,
and I can't write a standard tag to display it.

Is there a way to display not an action button, but just an image of the button that needs to be clicked?
Because I wrote [Alt] and [Left Alt], but nothing worked.