Hi,
I am aware that it is only a BETA feature. But unfortunately, the EV3 cannot be connected via Bluetooth when using https://makecode.mindstorms.com/. In the JavaScript Console the following error is displayed:
Failed to execute ‘open’ on ‘SerialPort’: Failed to read the ‘baudRate’ property from ‘SerialOptions’: Failed to read the ‘baudRate’ property from ‘SerialOptions’: Required member is undefined.
Best regards