I just started my nodejs express template buy cors is not working.

I used npm install cors --save

here is the file:

var express = require('express');
var cors = require('cors');
var app = express();

app.use(cors());

var corsOptions = {
  origin: 'https://example.com/',
  optionsSuccessStatus: 200
};

app.get('/', cors(corsOptions), function(req, res, next) {
    res.json({ message: 'hooray! welcome to our api!' });
});

app.get('/tt', function(req, res, next) {
    res.json({ message: 'hooray! welcome to our api!' });
});

var port = process.env.PORT || 3030;
app.listen(port);
console.log('Magic happens on port ' + port);

Now with the above code when I access localhost:3030/tt or / I still see the content and I shouldn't

What's wrong with this.. I just lost like 2 hours working on this.. :( At this time I would like not to use CORS, but in near future when my app is finished, I want to allow incoming calls only from my project, since this app will be my API.