title: WooCommerce Nodejs Wrapper returns undefined
body: <p>I am learning to work with the WooCommerce API and I am trying to modify the payment address and the shipping address of a user, but I get this error all the time and I do not understand what I am doing wrong.</p>
  <p>The error:</p>
  <pre><code>TypeError: undefined is not a function
  </code></pre>
  <p>This is my code:</p>
  <pre><code>var WooCommerceAPI = require(&quot;woocommerce-api&quot;);
  
  var api = new WooCommerceAPI({
    url: 'https://site.es/',
    consumerKey: 'ck_xxxx',
    consumerSecret: 'cs_xxxx',
    wpAPI: true,
    version: 'wc/v3'
  });
  
  const data = {
    first_name: &quot;James&quot;,
    billing: {
      first_name: &quot;James&quot;,
      postcode: &quot;99502&quot;,
   },
    shipping: {
      first_name: &quot;James&quot;,
      postcode: &quot;99502&quot;,
   }
  };
  
  api.putAsync('customers/33', data).then(function(result) {
    console.log(result);
  });
  </code></pre>
  <p>I would really appreciate any help, because really, I don't know what's wrong. I have read a lot about this and I don't see the error.</p>
  <p>Regards.</p>