This is how you provide an embed code, which will load a JavaScript file dynamically into the website and call a function from inside the file with externally passed params.
<script> (function () { var params = {}; // If you want to pass anything, to the called function var script = document.createElement("script"); script.type = "text/javascript"; if (script.readyState) { script.onreadystatechange = function () { if (script.readyState == "loaded" || script.readyState == "complete") { script.onreadystatechange = null; theFunctionInsideExternalScript(params); } } } else { script.onload = function () { theFunctionInsideExternalScript(params); } } script.src = "your-external-script-file.js"; document.getElementsByTagName("head")[0].appendChild(script) })(); </script>