Node.js server doesn’t start

I’m trying to start a server from my course but when I use node .server.js
nothing happens though I should get console info and see some basic page in the browser at localhost.
server.js

    const express = require('express'); 
const path = require('path'); 
const bodyParser = require('body-parser'); 
const cookieParser = require('cookie-parser'); 
const flash = require('connect-flash'); 
const session = require('express-session'); 
const routes = require('./routes/index'); 
 
const app = express(); 
 
app.set('views', path.join(__dirname, 'views')); 
app.set('view engine', 'pug'); 
 
app.use(express.static(path.join(__dirname, 'public'))); 
 
app.use(bodyParser.json()); 
app.use(bodyParser.urlencoded({ extended: true })); 

app.use(cookieParser()); 
app.use(session({ 
    secret: "tajnehaslo", 
    resave: false, 
    saveUninitialized: true, 
    cookie: {} 
})); 
app.use(flash()); 
app.use('/', routes); 
module.exports = app;

app.js

const app = require("./app");
app.set("port", process.env.PORT || 8080);
const server = app.listen(app.get("port"), () => {
  console.log(`Listening on ${server.address().port}`);
});

index.js

const express = require('express');
const router = express.Router();

const PagesController = require('../controllers/PagesControler');
const ApplicationsController = require('../controllers/ApplicationsController'); 

router.get('/', PagesController.home); 
router.post('/applications', ApplicationsController.store); 

router.get('/index', (req, res) => {
  res.render('login'); 
});

module.exports = router;

I have express installed