"{"code":4003,"message":"Access to view the document is denied","status":"failure"}"

"{"code":4003,"message":"Access to view the document is denied","status":"failure"}"

We want to use embed signing.

Trying to get the embed URL but it gives me this error.
Was able to get action_id and request_id .

$hostdomain = "remove_for_security_reasons.";


                $curl = curl_init();
                curl_setopt($curl, CURLOPT_URL, $url);
                curl_setopt($curl, CURLOPT_POST, true);
                curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
                curl_setopt($curl, CURLOPT_HTTPHEADER, array(
                    'Authorization: Zoho-oauthtoken ' . $token)
                    );