title: How can I call environment variables?
body: <p>in the .env file I set some variables
  //file .env</p>
  
  <pre><code>NAME="Darwin"
  </code></pre>
  
  <p>But when you call it in a js file, I get an undefined value
  //file index.js</p>
  
  <pre><code>console.log(process.env.NAME) 
  </code></pre>
  
  <p>and when executing node index.js</p>
  
  <pre><code>undefined
  </code></pre>
  
  <p>Can you explain me why this happens, Thanks.</p>