title: access key request from guzzle for oauth2 in laravel5.8
body: <p>i want to get access token from mailchimp oauth2 but in every try i was fail. Here i used guzzle and my actual request is</p>
  
  <p>curl --request POST \
  --url '<a href="https://login.mailchimp.com/oauth2/token" rel="nofollow noreferrer">https://login.mailchimp.com/oauth2/token</a>' \
  --data "grant_type=authorization_code&amp;client_id={client_id}&amp;client_secret={client_secret}&amp;redirect_uri={encoded_url}&amp;code={code}" \
  --include</p>
  
  <p>i already try curl and javascript but javascript request is not accepted by mailchimp
  this is code i used:</p>
  
  <pre><code>$http = new Client(['base_uri' =&gt; 'https://login.mailchimp.com/oauth2', 
   'defaults' =&gt; [
                  'exceptions' =&gt; false ],
      'header' =&gt; [
          'Accept' =&gt; 'application/json',
          'Content-Type' =&gt; 'application/x-www-form-urlencoded'
      ],
      'verify' =&gt; false
      ]);
      $result = $http-&gt;request('POST','/token', [
      'form_params' =&gt; [
          'grant_type' =&gt; 'authorization_code',
          'client_id' =&gt; $this-&gt;client_id,
          'client_secret' =&gt; $this-&gt;client_secret,
          'redirect_uri' =&gt; $this-&gt;redirect_uri,
          'code' =&gt; $code,
          ],
      ]);
      $response = $result-&gt;send();
      $responseBody = $response-&gt;getBody(true);
      var_dump($responseBody);
      die();
  </code></pre>
  
  <p>the expected actual result is:
  "access_token":"5c6ccc561059aa386da9d112215bae55","expires_in":0,"scope":null
  but my error Client error:
   <code>POST https://login.mailchimp.com/token</code> resulted in a <code>404 Not Found</code> response: