[fmbb]

The browser supports module imports. But your script must be of type ”module”: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe...

[TekMol]

Not with paths like 'lit' that is used here.

[uallo]

Import map:

https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/...

[TekMol]

The example does not use an importmap attribute.

Overall, the example does not seem like something that is supposed to run directly in the browser without some kind of intermediate step.

That is why I asked what the minimal number of steps would be to download the example and have it work locally.