How can you check who clicked a button?

well make it try checking like umm if you have a "String Value" for your tycoon where that string value putted who owns that tycoon.. then do a script like this, well this is what I recommend you doing

put a string value in the model where your script is in, that string value will serve to know the player who owns the tycoon you get me? so to do that put in that string value the name of the player in the value located in the properties of the string value, then do this script to know who clicked the button is the player

function onClick(clr)
    local owner = script.Parent.Value
    if clr.Name == owner.Value then
        print("The owner")
    end
end

script.Parent.Part.ClickDetector.MouseClick:connect(onClick)