Custom commands script, needs help with message? [closed]

local Admins = ("")
local Prefix = "/" 

for i,v in pairs(Admins) do--Get Some Admins
 game.Players(Admins)(i)).Chatted:connect(function(mag) --idk stuff here that you suold not change
  if mag:lower() == Prefix .. "shutdown" then
   game.Players:ClearAllChildren() -- Removes All The Players
   game.Workspace:ClearAllChildren() --- Removes All Things In Workspace
  end

  if mag:lower() == Prefix .. "ff me" then
   Inatance.new {"ForceField". game.Players(Admins(i)).Character)
  end

  if mag:lower() == Prefix .. "unff me" then
   while wait() do
   game.Players(Admins(i)).Character.ForceField:Destroy()
   end
  end

  if mag:lower() == Prefix .. "freeze me" then
   game.Players(Admins(i)).Character.Torso.Anchored = true
   game.Players(Admins(i)).Character.HumanoidRootPart.Anchored = true

  end
 end)
end

These are the commands ive made so far, but what I want to do is to make a command so that if I do !hi it broadcasts a message saying "Hi!".