HTML Guide for defer

The combination of type="module" and defer is not allowed. The type="module" attribute itself implies that the script should be executed in a deferred way, hence using the defer attribute is unnecessary and invalid.

Steps to Fix the Issue:

1. Remove the defer Attribute: When you use type="module", you should not include the defer attribute since module scripts defer automatically.

Incorrect Code:

<script type="module" defer src="example.js"></script>

Corrected Code:

<script type="module" src="example.js"></script>

The defer and async boolean attributes of the <script> element control how an external script should be executed once it has been downloaded. These attributes only make sense when referring to external scripts, so a src attribute must also be present to specify the location of the script.

Example:

<script defer src="app.js"></script>

If your script is not external, and is inlined within the HTML document, then you should remove the defer attribute, like in this example:

<script>
  console.log("hello");
</script>