Using shell object in gjs

shell_object_sample.js

#!/usr/bin/gjs
// SPDX-License-Identifier: MIT
// usage: gjs shell_object_sample.js

const { GIRepository, GLib, Gio } = imports.gi;

function findLib(path, prefix) {
  const libdir = Gio.File.new_for_path(path);
  const files = libdir.enumerate_children('', Gio.FileQueryInfoFlags.NONE, null);
  for (; ;) {
    const finfo = files.next_file(null);
    if (!finfo) break;
    if (finfo.get_file_type() == Gio.FileType.DIRECTORY && finfo.get_name().startsWith(prefix)) {
      return GLib.build_filenamev([path, finfo.get_name()]);
    }
  }
  return null;
}

GIRepository.Repository.prepend_library_path('/usr/lib64/gnome-shell')
GIRepository.Repository.prepend_search_path('/usr/lib64/gnome-shell');

GIRepository.Repository.prepend_library_path(findLib('/usr/lib64', 'mutter-'));
GIRepository.Repository.prepend_search_path(findLib('/usr/lib64', 'mutter-'));

const { Shell } = imports.gi;
const appSys = Shell.AppSystem.get_default();
print(appSys.get_installed().map(x => x.get_name()).join('\n'));

Running Shell.AppSystem.get_default().get_running().map(x => x.get_name()).join('\n') in lg (alt+F2 then type lg), is there output?

The output is r(0) = Firefox Alacritty ..... I mean the command works if i run this way.