how we should load javascript in html code example

Example 1: how to use javascript in html

<!-- include an external javascript document -->
<script src="myJavaScript.js" charset="utf-8"></script>

<!-- JavaScript inside html element -->
<script>
  console.log("This is JavaScript");
</script>

Example 2: How to add js file to a site through url

var jsFile = document.createElement("script");
jsFile.src = "homePage.js";  // it can be path also  "{themes('/scripts/homePage.js')}"
document.body.appendChild(jsFile);  //append it as src to body