How to get message value sent via res.end(message) in ajax?

Question

Node.js

How to get the value for further processing and correct display in ajax
if the data was sent from node.js with res.end(...)?

In particular, this point is of interest:

var xhr = new XMLHttpRequest();
      xhr.open("GET", "/subscribe", true);

      xhr.onload = function() {
        var li = document.createElement('li');
        li.textContent = this.responseText;
        message.appendChild(li);

        subscribe();
      };

      xhr.onerror = xhr.onabort = function() {
        setTimeout(subscribe,300);
      };

      xhr.send('');

Here, for some reason, the res.end(message) passed from the node is not displayed on the screen.
Screenshot with an error:



The question is settled. Found a way out.

Answer 1

app.get('/getapi', function(req, res, next){
    let body = req.body;
    return res.json({data: body});
});

$.get("/getapi",
    {
        param1: "param1",
        param2: "param2"
    },
    onAjaxSuccess
);
function onAjaxSuccess(data){
    console.log(data);
}