Cannot find module 'nodemailer'

I'm using the Zapier Code application, I need to send an email receiving trello parameters, I'm using a javascript encoding along with node.js, but when I try to find the nodemailer module I always get the error that it can not be found .. .

The error always points to this line of code:

Var nodemailer = require ('nodemailer');

via Fábio Junio Alves Sousa