When I try to use the framework I am seeing this error in the browser:

 Failed to resolve module specifier "@lit/reactive-element"

In my html thymeleaf template I have:

<script type="module" th:src="@{/js/simple-greeting.js}"></script>

and in the simple-greeting.js I am referencing the lit framework like:

import {html, css, LitElement} from '/webjars/lit/index.js';

the "simple-greeting.js" is included with my static js. And the Lit dependency is included as a webjar.

I feel like I'm missing something fundamental (hopefully simple) with how the JS frameworks import/export modules. Is there some sort of build process I need to do to leverage the JS framework? (I really hope not)