const el = document.createElement('pwa-update');
        document.body.appendChild(el);
        if('serviceWorker' in navigator) {
            var querystring = document.currentScript.src.substring( document.currentScript.src.indexOf("?") );
            var urlParams = new URLSearchParams( querystring );
            if (urlParams.get('base_adm')){
                navigator.serviceWorker
                    .register('/pwabuilder-sw.js', {scope: '/'})
                    .then(function() { console.log("Service Worker..."); });
            }
        }