exception while importing module in ember js

I need to remove diacritics from string in emberjs app. I found a plugin for this: fold-to-ascii but I don't know how to use it in my app.

I added this plugin via npm and it is visible under node_modules folder in my app

In docs usage of this plugin is:

var foldToAscii = require("fold-to-ascii");
foldToAscii.fold("★Lorém ïpsum dölor.")

but i get an exception:

Uncaught Error: Could not find module fold-to-ascii

What am I doing wrong ?