title: Unable to refresh access token of paypal
body: <p>I am getting invalid refresh token using this url <code>https://api-m.sandbox.paypal.com/v1/identity/openidconnect/tokenservice?grant_type=refresh_token&amp;refresh_token=A21AAINhl7...._p4r5fZe1LJw</code></p>
  <p>My params:</p>
  <pre><code>grant_type=refresh_token
  refresh_token=&quot;A21AAINhl7...._p4r5fZe1LJw&quot;
  </code></pre>
  <p>header:</p>
  <pre><code>Content-Type=application/x-www-form-urlencoded
  
  basic auth 
  clientid
  client secret
  </code></pre>
  <p>output</p>
  <pre><code>{
  &quot;error_description&quot;: &quot;Unable to refresh access token&quot;,
  &quot;error&quot;: &quot;invalid_request&quot;,
  &quot;correlation_id&quot;: &quot;c58cc1...b0c5a&quot;,
  &quot;information_link&quot;: &quot;https://developer.paypal.com/docs/api/#errors&quot;
  }
  </code></pre>
  <p>Or how can I get refresh token using paypal api? Refresh token value is expired access token I have set in this url so, is that right?</p>