How to bind "a" tag to HTML element using express.js?

Question

JavaScript

If you bind the "a" tag to an HTML element as usual (for example, to the class container ), then express will output the following: Cannot GET /.container
If there was an image, I would do this:

app.get("/whatsapp.png", (req, res) => {
    res.sendFile(path.join(__dirname, "images", "whatsapp.png"));
});

But how do you highlight an HTML element?