* Install the 1.39.5 [emsdk](https://kripken.github.io/emscripten-site/docs/getting_started/downloads.html), which is known to work. Do not use the system-provided `emscripten` package, because it contains a version that is too old.
See [tdweb](https://www.npmjs.com/package/tdweb) or [README.md](https://github.com/tdlib/td/tree/master/example/web/tdweb/README.md) for package documentation.