title: Salesforce REST API upsert not updating or inserting a record
body: <p>I am trying to update and insert Contacts using the external ID and patch method with the REST API.</p>
  <p>If I try to use an existing record I just get back the record JSON and nothing gets updated. If I use an none existent external ID I get an error:</p>
  <pre><code>[
      {
          &quot;errorCode&quot;: &quot;NOT_FOUND&quot;,
          &quot;message&quot;: &quot;The requested resource does not exist&quot;
      }
  ]
  </code></pre>
  <p>Authentication works as I can make GET calls and get back the data fine.
  I am not sure where to go from here. Any leads will be appreciated.</p>
  <p><a href="https://i.stack.imgur.com/fZPOZ.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/fZPOZ.png" alt="Postman screenshot" /></a></p>