How does the script automatically select the UI interface language based on the windows system?

I saw a script here.
https://github.com/gsingelmann/indd_autocolumn/tree/master 

The author (Gerald Singelmann) seems to have set "en" "de" "it" three languages, is it possible to automatically choose to display the appropriate language interface according to different windows systems.
I tried to add cn and nothing seems to change anything.

var sAutoColumn = {  en: "AutoColumn2...", de: "AutoSpalte2...", it: "AutoColumn2..."}

if (app.selection.length) {
    app.doScript(autoSpalte, undefined, undefined, UndoModes.ENTIRE_SCRIPT, localize(sAutoColumn));
}