Run it
Copy the script and paste it into your executor.
local players = game:GetService("Players")
local localplayer = players.LocalPlayer
local chatservice = game:GetService("Chat")
localplayer.Chatted:Connect(function(msg)
local args = msg:split(" ")
if args[1] == ":talk" and args[2] and args[3] then
local target = args[2]
local message = msg:sub(#args[1] + #args[2] + 3)
if target == "all" then
for _, player in ipairs(players:GetPlayers()) do
if player.Character and player.Character:FindFirstChild("Head") then
chatservice:Chat(player.Character.Head, message, Enum.ChatColor.White)
player = players:(target)
player player.Character player.Character:()
chatservice:(player.Character.Head, message, .ChatColor.White)
)
say :talk all {message}

Universal