import { setupTitlebar, attachTitlebarToWindow } from "custom-electron-titlebar/main";

// setup the titlebar main process
setupTitlebar();

function createWindow() {
  // Create the browser window.
  const mainWindow = new BrowserWindow({
    width: 800,
    height: 600,
    //frame: false, // needed if process.versions.electron < 14
    titleBarStyle: 'hidden',
    /* You can use *titleBarOverlay: true* to use the original Windows controls */
    titleBarOverlay: true,
    webPreferences: {
      sandbox: false,
      preload: path.join(__dirname, 'preload.js')
    }
  });
  
  ...

  // attach fullScreen(f11 and not 'maximized') && focus listeners
  attachTitlebarToWindow(mainWindow);
}

import { Titlebar } from "custom-electron-titlebar";

window.addEventListener('DOMContentLoaded', () => {
  // Title bar implementation
  new Titlebar();
});