“This tutorial relies on a laptop or device that runs chrome or chromium:
A subset of the Web Bluetooth API is available in Chrome OS, Chrome for Android 6.0, Mac (Chrome 56) and Windows 10 (Chrome 70).
This means that it is impossible to connect an iPhone f.e. using this Bluetooth protocol to the micro:bit, there might be a possibility that it works with the WebBLE app for iOS but I haven’t tried it. on most Android devices it works when you install the chrome browser. It also needs to be run in a secure environment (meaning https:// ), so the p5 web editor is perfect for that. Check https://web.dev/bluetooth/ for the latest updates on the protocol.”