3d Innovation submit coupon JS(for all pages!)

<script>
(function() {
    var COUPON_TEXT = 'FB25';
    var URL = window.location.origin + '/checkout/cart/couponPost/?remove=0&coupon_code=' + COUPON_TEXT;
    var data = null;
    var xhr = new XMLHttpRequest();
    xhr.withCredentials = true;
    xhr.addEventListener('readystatechange', function () {
        if (this.readyState === 4) {
            window.location.reload(true);
        }
    });
    xhr.open('POST', URL);
    xhr.setRequestHeader('cache-control', 'no-cache');
    xhr.send(data);
})();
</script>