You'll have to configure Mongoose for your desired platform, this example runs on the unix port and Mongoose detects it as a known architecture and hence configures itself to use sockets and time base. For other platforms, you'll have to do your homework (there's plenty of Mongoose examples for several platforms); also check respective MicroPython build instructions.

Check _thread support for more advanced usage

https://docs.micropython.org/en/latest/develop/cmodules.html