PlayerAddedEarly event - how can I use it?

If I were to code the following:

Allowed = {"XanthicDragon", "InsertNameHere"}
k = false

function KickRandomPlayer()
	local Players = game:GetService("Players").NumPlayers --Is that the variable? I may be wrong
	local random = math.random(1, Players)
	game.Players:GetChildren()[random]:Kick()
end

game:GetService("Players").PlayerAddedEarly:connect(function (Player)
	for _,v in ipairs(Allowed) do
		if Player.Name == v then
			k = true
		end
	end
	if k then
		KickRandomPlayer()
		k = false
	end
end)

Would this event fire and kick a random player if one of the players found in "Allowed" were attempting to join a full server?

No it would not work, game.Players.PlayerAddedEarly is not a real function.

No. While the event apparently exists, it also is apparently locked.

You will not be able to use it.