ES6 module Import giving "Uncaught SyntaxError: Unexpected identifier"

From what I can see you are trying to load the file menu.module.js while it's actually named menu.js.

PS: From what I recall you could also drop the .js from the import statement.

As @Bergi mentioned in the comment, adding type="module" to the main.js import line in the HTML solved the issue. All is working now. I.e.

<script type="module" src="assets/js/main.js">

Thanks to all of you who responded and tried to help.