I found this:

Introduction to the NGINX JavaScript Module
https://www.nginx.com/blog/introduction-nginscript/

Is that module needed now? I think there are people using nginx who do not use that module.

I cannot get javascript to work with nginx. This is make my moodle install impossible.

Supposedly this install the module.

sudo apt-get install nginx-module-njs

Does not work for me.

# apt-get install nginx-module-njs
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package nginx-module-njs