index.js

let electron = require("electron")
let app = electron.app
let BrowserWindow = electron.BrowserWindow

app.on('ready', () => {
  var mainWindow = new BrowserWindow({
    show: false
  });
  mainWindow.loadURL("https://google.com");
  mainWindow.webContents.once('did-finish-load', () => {
    mainWindow.show();
    mainWindow.close();
    var screen = require('electron').screen
    var screen_width = screen.getPrimaryDisplay().workAreaSize.width
    var screen_height = screen.getPrimaryDisplay().workAreaSize.height

    newWindow = new BrowserWindow({
      show: false
    });
    newWindow.loadURL("https://google.com");
  })
})