Rest 获取带有数据的信封草稿

如何通过REST API获取包含表单字段数据的信封草稿以在我的系统上显示预览，我在DocuSign sandbox上使用PHP API，但是当信封id处于草稿状态时，PDF请求响应出现错误

 <?php
$client = new http\Client;
$request = new http\Client\Request;
$request->setRequestUrl('https://demo.docusign.net/restapi/v2.1/accounts/7808658/envelopes/{{envelopeId}}/documents/{{documentId}}');
$request->setRequestMethod('GET');
$request->setOptions(array());
$request->setHeaders(array(
  'X-DocuSign-Authentication' => '{"Username":"x@xxx.com","Password":"doOTcFj08wl/xO6uR2ZLX6+rOaE=","IntegratorKey": "xxxx-xxxx-xx-a075-xxx"}',
  'Content-Type' => 'application/json'
));
$client->enqueue($request)->send();
$response = $client->getResponse();
echo $response->getBody();

$client = new http\Client;
$request = new http\Client\Request;
$request->setRequestUrl('https://demo.docusign.net/restapi/v2.1/accounts/7808658/envelopes/{{envelopeId}}/documents/{{documentId}}');
$request->setRequestMethod('GET');
$request->setOptions(array());
$request->setHeaders(array(
  'X-DocuSign-Authentication' => '{"Username":"x@xxx.com","Password":"doOTcFj08wl/xO6uR2ZLX6+rOaE=","IntegratorKey": "xxxx-xxxx-xx-a075-xxx"}',
  'Content-Type' => 'application/json'
));
$client->enqueue($request)->send();
$response = $client->getResponse();
echo $response->getBody();

如果您回显/调试此字符串
'https://demo.docusign.net/restapi/v2.1/accounts/7808658/envelopes/{{envelopeId}}/documents/{{documentId}}'

您会注意到，您没有传递信封ID或文档ID，而是以文本形式传递，请传递信封ID和文档ID，API应该可以正常工作
您可以分享您正在使用的导致错误的代码吗？错误是什么？谢谢你的帮助。我有带草稿信封的pdf，我只需检查帐户设置中的选项，并遵循您的建议。