Cannot find module './fonoapi.node.js' but when listing, the module is shown

I am trying to use fonoapi-nodejs. I installed it using npm install fonoapi-nodejs --save.

Then when I try to acces it using var fonoapi = require('./fonoapi.node.js');

It gives me an error Error: Cannot find module './fonoapi.node.js' and when I list the npm packages using npm list --depth=0 the package ├── body-parser@1.16.1 ├── cookie-parser@1.4.3 ├── debug@2.6.3 ├── ejs@2.5.6 ├── express@4.14.1 ├── fonoapi-nodejs@0.1.1 ├── morgan@1.7.0 └── serve-favicon@2.3.2 is listed there.

via theanilpaudel