Natives in Javascript

This page says you can use natives in javascript, which means there would be less need to relay a bunch of stuff between NUI code and Lua code.
https://wiki.fivem.net/wiki/List_of_JavaScript_functions
However I just can’t figure out how to make it work.
I always get a “functionname not defined” error. Is there anything I need to to access these functions?

no?

NUI isn’t related to the actual JS scripting runtime.