Test

(function(d, s, id){
if (d.getElementById(id)) return;
var js = d.createElement(s);
js.id = id;
js.src = “https://www.gstatic.com/dialogflow-console/fast/df-messenger/prod/v1/df-messenger.js”;
d.head.appendChild(js);
}(document, ‘script’, ‘df-messenger’));