Express Js template not rendering

Question

Initially the index.ejs template was running but all of a sudden it just could not render the template anymore. I have no idea where the error could be.

I am getting the error message: Cannot GET /

app.get('/index', function(req, res) {
    fs.readFile('items.json', function(error, data) {
        if (error) {
            res.status(500).end();
        } else {
            res.render('index.ejs', {
                stripePublicKey: stripePublicKey,
                items: JSON.parse(data),
            });
        }
    })
})
app.listen(3000);