Ubuntu chromium and web ide

Ahh - https://www.npmjs.com/package/espruino might be handy.

Check that which node returns something, and then do:

sudo setcap cap_net_raw+eip $(eval readlink -f `which node`)

That gives Node.js the permissions to access Bluetooth without running as a superuser.

Can you also try ./espruino-cli.js --list --verbose and see if it shows any errors?

Might be that somehow NPM hasn't installed the relevant Bluetooth stuff (and sorry, I should have mentioned you can do npm install espruino -g to install it globally so you don't have to manually execute the JS file.