I downloaded local copy of npm package and extracted it on desktop.
Then I used npm install /directory/ to install it.
What I noticed is that when I remove desktop directory, app says it can't find installed module. After further investigation I noticed that package is in node_modules but it has arrow next to it and it says "symbolic link" which I suppose is a link to desktop directory with this package.
How do I install it independently so that it is fully contained in node_modules allowing me to remove desktop copy?
Turns out you can use
npm pack /path/to/package
This will cause npm to pack package into a .tgz file.
Then you can install it from a .tgz file using a standard
npm install /path/to/file.tgz
This will force npm to create a local copy in node_modules without symbolic link