requests with js

function generateImage () {
    const xhr = new XMLHttpRequest();
    const url = 'https://api.desktoppr.co/1/wallpapers';

    // Handling request
    xhr.responseType = 'json';
    xhr.onreadystatechange = function () {
        if (xhr.readyState === XMLHttpRequest.DONE) {
            var images = xhr.response.response;
            var randomNumber = Math.floor(Math.random() * 19);
            var wallpaper = document.getElementById('myWallpaper');
            var image = images[randomNumber].image.url;
            wallpaper.src = image;
        }
    }

    // Sending request
    xhr.open('GET', url);
    xhr.send();
}

var button = document.getElementById('myButton');
button.addEventListener('click', generateImage);