Sorry about this, the tutorial itself is pretty old and probably hasn’t been checked for a while. Both the socket.io and PlayCanvas engine has been updated since then.
I’ve created an issue so we don’t forget about it: Multiplayer tutorial no longer works · Issue #123 · playcanvas/developer.playcanvas.com · GitHub
The documentation is open source so if you would like to help us improve or even just report an issues that you have, that would be a great help: GitHub - playcanvas/developer.playcanvas.com: Developer resources website for PlayCanvas
The other language versions are done by the community so they can be a lot behind the English versions. Not 100% what to do about that going forward TBH as we go through improving the documentation and platform.
Yeah, I’ve been wanting to expand it out quite a bit to do a basic .io game with a shared game state. We are quite a small team and unfortunately it’s been a balance of priorities.