Need help on keybindings?

Well, I'm trying to make a crouch animation and i want the button that triggers the animation "Alt" only problem is I don't know the value of the alt button. Could anyone tell me?

[For example shift is considered 0"

You can find the value yourself, for any key, with this script!

local mouse = game.Players.LocalPlayer:GetMouse()

mouse.KeyDown:connect(function(key)
print(key)
end)

It's a very simple script that shouldn't need any explaining. If you do need explanation, I can add it.

EDIT: You need instructions on how to make a KeyDown event? Just use the above code and remove the print(), and add a conditional statement (if conditions then) that checks the value of the key, like if key == "0" then. Hope it helped!

Sadly I need instructions.