const iframe = document.querySelector('iframe'); if (iframe) { const getCookie = name => document.cookie.split('; ').find(row => row.startsWith(name + '='))?.split('=')[1]; const params = ['utm_source','utm_medium','utm_campaign','utm_content','gclid'] .map(k => `${k}=${getCookie(k) || ''}`).join('&'); iframe.src += (iframe.src.includes('?') ? '&' : '?') + params; }