add script file in html code example
Example 1: import js in html
<script type="text/javascript" src="yourfile.js"></script>
Example 2: include script in html
<script type="text/javascript" src="/path/to/script.js"></script>
Example 3: how to link javascript to html
<script src="PathToYourFile.js"> </script>
Example 4: how to add script in html head
<script src="script.js" defer></script>
<!--just add defer attribute so script will execute at last-->