How to make a working gui button using onclicked()?

Just start i'm really new with scripting so sorry if some of my questions are really easy.

I've been trying to make a rocket ship and in order to launch it I want to use an on screen button that is clicked to start the launching process.

Located in Startgui I have ScreenGui > TestButton > Script

The script contains

function onClicked() print("Orefef") end script.Parent.MouseButton1Click:connect(onClicked)

Whenever I click on the button, "Orefef" does not print so obviously the button does not work. Probably a really dumb mistake but any help would be great.

Like Feahren said in the comments, you need to use a LocalScript for the button to work from a Gui (these are client specific)

Local Script

script.Parent.Activated:Connect(function()
	print("Orefef")
end)

Activated is preferred since it works on all devices, not just computers.

This script is fine if you want only the player that clicked the button to see the launch, otherwise, if all players will see it, you need to use Remote Functions & Events as outlined here: https://wiki.roblox.com/index.php?title=Remote_Functions_%26_Events

Example of Remote Event

Local Script

local remote = game.ReplicatedStorage.RemoteEvent

script.Parent.Activated:Connect(function()
	print("Orefef")
	remote:FireServer()
end)

Server Script

local remote = game.ReplicatedStorage.RemoteEvent

remote.OnServerEvent:Connect(function(player)
	-- Causes Rocket to Launch
end)

For the above example, I have a Remote Event in Replicated Storage named "RemoteEvent"