How do I make the server say something when an event occurs???

Alright, so first off, I want to say I did read the wiki on > SetCore. It didn't help.

game.StarterGui:SetCore("ChatMakeSystemMessage", {
	Text = "Welcome to my game!"; -- Required. Has to be a string!
	Color = Color3.new(0, 1, 1); -- Cyan is (0, 255 / 255, 255 / 255). Optional, defaults to white: Color3.new(255 / 255, 255 / 255, 243 / 255)
	Font = Enum.Font.SourceSans; -- Optional, defaults to Enum.Font.SourceSansBold
	FontSize = Enum.FontSize.Size24; -- Optional, defaults to Enum.FontSize.Size18
})

This is what the wiki supplies for us. I tried adding a function to it. Here's an example of what I tried to do:

game.Players.PlayerAdded:connect(function()

game.StarterGui:SetCore("ChatMakeSystemMessage", {
	Text = "Welcome to my game!"; -- Required. Has to be a string!
	Color = Color3.new(0, 1, 1); -- Cyan is (0, 255 / 255, 255 / 255). Optional, defaults to white: Color3.new(255 / 255, 255 / 255, 243 / 255)
	Font = Enum.Font.SourceSans; -- Optional, defaults to Enum.Font.SourceSansBold
	FontSize = Enum.FontSize.Size24; -- Optional, defaults to Enum.FontSize.Size18
})
end

This didn't work. I wasn't sure if it would. How would I set the text to... I don't know... Actually work -.-

Also I put all of this in a > LocalScript because somone told me that > SetCore only works in a > LocalScript

An Explanation/Example would be highly appreciated.

This is the wiki page I read:

Also, I'm not necessarily asking for a script; just something to help me out.