I'm afraid I don't think they're built in by default because of the pain of supporting them.
You could either use an official board like the Espruino Pico or WiFi, or could possibly try and build it in yourself?
@Gordon started
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
I'm afraid I don't think they're built in by default because of the pain of supporting them.
You could either use an official board like the Espruino Pico or WiFi, or could possibly try and build it in yourself?