Sending a post request from frontend

[GeorgiDimitrov87]

I am trying to send a post request from templates/cms/media.html but it is not working.

var xhr = new XMLHttpRequest();
    xhr.open("POST", "localhost/analytics", true);
    xhr.setRequestHeader('Content-Type', 'application/json');
    xhr.onload = function () {
        // Request finished. Do processing here.
        console.log("sent");
    };
    xhr.onerror = function (error) {
        // ** An error occurred during the transaction
        console.log(error);
    };
    xhr.send(JSON.stringify(json));

How can I send analytics data from the video player?