Babyteva add to cart

<script>
(function() {

    function adoricAddToCart(productId) {
        console.log('product added - ', productId);
        var formData = new FormData();
        formData.append('quantity[]', 1);
        formData.append('option', 'com_virtuemart');
        formData.append('view', 'cart');
        formData.append('virtuemart_product_id[]', productId);
        var xhr = new XMLHttpRequest();
        xhr.withCredentials = true;
        xhr.addEventListener('readystatechange', function () {
            if (this.readyState === 4) {
                console.log(this.responseText);
            }
        });
        xhr.open('POST', 'https://babyteva.co.il/index.php?option=com_virtuemart&nosef=1&view=cart&task=addJS&format=json&lang=he');

        xhr.setRequestHeader('cache-control', 'no-cache');
        xhr.send(formData);
    }

    if (window.Element && !Element.prototype.closest) {
        Element.prototype.closest = function(s) {
            var matches = (this.document || this.ownerDocument).querySelectorAll(s),
                i,
                el = this;
            do {
            i = matches.length;
            while (--i >= 0 && matches.item(i) !== el) {};
            } while ((i < 0) && (el = el.parentElement));
            return el;
        };
    }
    var currentCampaignRepeater = document.querySelector('.' + self.identifier + ' .repeater-content');
    currentCampaignRepeater.addEventListener('click', function(event) {
        var productItem = event.target.closest('.repeater-item');
        event.preventDefault();
        if (event.target.getAttribute('role') === 'button' && productItem) {
            var productInformation = JSON.parse(productItem.dataset.productInfo);
            var  productId = getUrlParameter('variant', productInformation.link);
            adoricAddToCart(productId);
        }
    });
})();
</script>