How to make a water shadow prompt script

[PVP Azure]

Every 5 minutes, a message "Hi" will be sent in the chat bar, only you can see it

[CzechHek]

module = {
    name: "Prompt",
    onLoad: function () {
        timer = interval(5000, function () {chat.print("Hi")});
    },
    onUnload: function () {
        timer.cancel();
    }
}

script.import("Core.lib");