Javascript – How to add favicon for Content-Type: application/json

I am using node.js and implementing an API that returns a response as Content-Type: application/json like this:

module.exports={
    api: (req, res) => {
        let data = {"data": [1, 2, 3]};
        res.status(200).json(data);
    }
}

But, there is no favicon that can be viewed when trying that API on the browser. I see another website that can get this done.

How can add a favicon on the Node.js API with Content-Type: application/json?