groo gtm write cookie with userData

<script>
        (function () {
        var cookieName = 'showCampaign';
        var expiresTime = 3600 * 1000 * 2;
        if (!getCookie(cookieName)) {
            getUserInformation();

        }
        function getCookie(name) {
            try {
                let matches = document.cookie.match(new RegExp(
                    "(?:^|; )" + name.replace(/([\.$?*|{}\(\)\[\]\\\/\+^])/g, '\\$1') + "=([^;]*)"
                ));
                return matches ? decodeURIComponent(encodeURIComponent(matches[1])) : undefined;
            } catch (err) { console.log(err) };
        }
        function writeCookie(key, value, expires) {
            var now = new Date();
            var time = now.getTime();
            time += expires;
            now.setTime(time);
            var cookieString = key + '=' + value + '; expires=' + now.toUTCString() + ';';
            window.document.cookie = cookieString;
            return value;
        };

        function utf8_to_b64(str) {
            return window.btoa(unescape(encodeURIComponent(str)));
        }

        function getUserInformation() {
            var data = new FormData();
            data.append("file", "general");
            data.append("action", "get_async_user_data");

            var xhr = new XMLHttpRequest();
            xhr.withCredentials = true;

            xhr.addEventListener("readystatechange", function () {
                if (this.readyState === 4) {
                    var userData = JSON.parse(this.responseText);
                    if (userData.err) {
                        console.error(userData.err);
                        return;
                    }
                    if (userData.user_id !== -1) {
                        writeCookie(cookieName, this.responseText, expiresTime);
                    }
                }
            });

            xhr.open("POST", "https://www.groo.co.il/_ajax/ajax.index.php");
            xhr.send(data);
        }

    })();
</script>