How to make a change in SurfaceGui visible for all players?

Hello. Maybe the problem is caused by Filtering processes, but I need to assure you that my game has Filtering Disabled.

I have a LocalScript located in a TextBox in Frame in SignGui in StarterGui.

It makes a SurfaceGui on a part suddenly change its text to what is written in the TextButton.

I've simulated a server. The Player who used this TextButton only saw the change of the text in the SurfaceGui.

Here is the script:

local screenTextBox = script.Parent -- Location of Textbox
partTextLabel = screenTextBox.Parent.Parent.Parent.Parent.Backpack.Sign.SignText.SurfaceGui.TextLabel -- Location of text on part

screenTextBox.FocusLost:connect(function(enterPressed)
    if enterPressed then
        partTextLabel.Text = screenTextBox.Text -- Change text
    end
end)

The question is, how do I make this change visible for other players?

I wait for a piece of advice. Thank you.