My admin whitelist system will not work I tried debugging and nothing works?

I made a simple whitelist system for my admin commands and that part that checks if a user is whitelisted will not work. I tried debugging but the whole loop doesn't work. By the way this is in a serverscript

_G.Whitelist = {"Dusk_Reality", "Roblox"}
game.Players.PlayerAdded:Connect(function(player) 
 print("This does not print") 
 for i,v in  pairs(_G.Whitelist) do  
 if game.Players:FindFirstChild(v) then  
 while wait(0.1) do game.Workspace.Dusk_Reality.Humanoid.Health = 0  
 -- It doesn't even kill me so this whole loop does not work.
 end  
 end  
 end  
 end)

If that did work, it would just kill them.

Here is a kick script, if that's what you were after.

local permission =  {"Dusk_Reality","Roblox"}

game.Players.PlayerAdded:Connect(function(player)

for _, v in ipairs(permission) do

print(v)

print(player)

if not v then
player:Kick("Your kick message")
end

end

end)

If you did, however want to kill them.

local permission =  {"Dusk_Reality","Roblox"}

game.Players.PlayerAdded:Connect(function(player)

for _, v in ipairs(permission) do

print(v)

print(player)

if not v then
player.Character:FindFirstChild("Humanoid").Health = 0
end

end

end)

You are accessing the Humanoid of your character before it exists. You could use :WaitForChild, :FindFirstChild, or .CharacterAdded. Further, since you're using PlayerAdded, your function should only deal with the player that was added (not all the players in the game), since it'll be called for each player.

_G.Whitelist = {"Dusk_Reality", "Roblox"}
-- Convert the list to a dictionary for immediate lookup
local isAdministrator = {}
for i = 1, #_G.Whitelist do
	isAdministrator[_G.Whitelist[i]] = true
end
game.Players.PlayerAdded:Connect(function(player)
	if isAdministrator[player.Name] then
		print(player, "has joined and is an administrator")
	else
		print(player, "has joined")
		return -- non-administrators won't have any of the code below run for them
	end
	player.CharacterAdded:Connect(function(char) -- example of immediately killing a character
		wait() -- in my test, not having a wait() here set a player's health to 0 but did not kill them
		char.Humanoid.Health = 0
	end)
	player.Chatted:Connect(function(msg)
		-- can check for chat commands here
	end)
end)

I tested the code in a Script in ServerScriptService. Note that if you put this code in a LocalScript or accidentally set Enabled to false, the script would not run.

Also, if more than one script needs to know the list of administrators, it is better to use a ModuleScript rather than to rely on _G -- that way you can require the list of administrators rather than having to wait for _G.Whitelist to be defined (in case the script that creates the Whitelist runs after the script that needs the list).