express session Works in local but does not work on a remote server

I used the same code in local, it worked fine but when I used it on a remote server it did not work

this is the code of index.js

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


var auth = function(req, res, next) {
    console.log(req.session.admin);
    if (req.session && req.session.admin)
        return next();
    else
        return res.redirect('/');
};

router.get('/qwerty',auth, function(req, res) {
    console.log('Welcome '+req.session.user);
    res.render('data');
});

router.get('/', function(req, res) {
    res.render('login');
});

module.exports = router;

and this is the one used for authentification

router.post('/loginweb',function(req, res) {
    Users.findOne({userName:req.body.username,password:req.body.password},function(err, data){
        if (err)
            console.log(err);
        else{
            if (!data)
            //console.log('Not found');
                res.json({'success':'false'})
            else{
                console.log(data);
                var name=data.firstName + ' ' + data.lastName;
                req.session.user = name;
                req.session.admin = true;
                console.log(req.session);
                res.json({'success':'true','id':data._id,'name':name});
            }
        }
    })
});

app.js

    var express = require('express');
    var path = require('path');
    var favicon = require('serve-favicon');
    var logger = require('morgan');
    var cookieParser = require('cookie-parser');
    var bodyParser = require('body-parser');
    var hbs = require("express-handlebars");
    var cors = require('cors');

    var index = require('./routes/index');
    var users = require('./routes/users');
    var api = require('./routes/api');

    var session = require('express-session');
    var FileStore = require('session-file-store')(session);

    var app = express();

    app.use(cors());
    app.options('*', cors());

    // view engine setup
    app.engine('.html',require('ejs').__express);
    app.set('views', path.join(__dirname, 'views/webpage'));
    app.set('view engine', 'html');
    app.use("/css", express.static(__dirname + '/views/webpage/css'));
    app.use("/js", express.static(__dirname + '/views/webpage/js'));
    app.use("/img", express.static(__dirname + '/views/webpage/img'));



    // uncomment after placing your favicon in /public
    //app.use(favicon(path.join(__dirname, 'public', 'favicon.ico')));
    app.use(logger('dev'));
    app.use(bodyParser.json());
    app.use(bodyParser.urlencoded({ extended: false }));
    app.use(cookieParser());
    app.use(express.static(path.join(__dirname, 'public')));
    //app.use(express.cookieParser);
    app.use(session({secret: 'maxa',cookie: { maxAge: 60000, httpOnly: false, path: '/' },saveUninitialized:false,resave:false}));


    app.use('/', index);
    app.use('/users', users);
    app.use('/api', api);


    // catch 404 and forward to error handler
    app.use(function(req, res, next) {
      var err = new Error('Not Found');
      err.status = 404;
      next(err);
    });

    // error handler
    app.use(function(err, req, res, next) {
      // set locals, only providing error in development
      res.locals.message = err.message;
      res.locals.error = req.app.get('env') === 'development' ? err : {};

      // render the error page
      res.status(err.status || 500);
      res.render('error');
    });

    module.exports = app;

client side :

$(document).ready(function () {
    $("#btn-login").click(function(){

        jQuery.support.cors=true;
        event.preventDefault();
        var username = $("#username").val();
        var password = $("#password").val();
        $.post("http://www.example.com/api/loginweb",
        {
            'username': username,
            'password': password
        },
        function(data){
            console.log(data);
            if(data.success=='false'){
                alert('Wrong username or password');
            }else{
                self.location.href = '/qwerty';//'http://www.example.com/qwerty';
            }
        });
    });
});

the session is undefined in the /qwerty method but defined in the /loginweb method

via khadhraoui Firas