XyOrb needs a server.

src/orb.js is a real ES module, and a file:// document has an opaque origin. Every current engine fetches <script type="module"> with CORS, which an opaque origin can never satisfy — so the import is refused before any of this page runs. That is a browser rule; there is no build step involved and no flag inside the library that changes it.

Run any static server from this folder and reload:

python -m http.server 8000     # or:  npx serve .