Oauth Hubspot Webhooks：重定向身份验证&；错误的授权类型消息

我正在尝试在Hubspot中添加自定义应用程序。我正在使用PHP。我有：

• Hubspot应用程序
• 一个有效的webhook URL
• 包含以下代码的重定向URL

  $url = 'https://api.hubapi.com/oauth/v1/token';
  $code =  $_GET['code']; // Getting code parameter from redirect URL
  //echo $code;
  $fields = array();
  $fields['grant_type'] = 'authorization_code'; // Have also tried 'refresh_token' - same result
  $fields['client_id'] = '{CLIENT_ID}';
  $fields['client_secret'] = '{CLIENT_SECRET}';
  $fields['redirect_uri'] = '{REDIRECT_URI}';
  $fields['code'] = trim($code);
  //$fields['refresh_token'] = trim($code);  // Have also tried 'refresh_token' - same result
  
  $request_type = 'POST';
  
  $ch = curl_init($url);
  curl_setopt($ch, CURLOPT_HTTPHEADER, array('Accept: application/json', $headers));
  curl_setopt($ch, CURLOPT_HEADER, 0);
  curl_setopt($ch, CURLOPT_CUSTOMREQUEST, POST); 
  curl_setopt($ch, CURLOPT_TIMEOUT, 30);
  curl_setopt($ch, CURLOPT_POST, 1);
  if($fields){
      curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($fields));
  }
  curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
  $return = curl_exec($ch);
  curl_close($ch);
  echo var_dump ($return);    
  

• 我的理解是Hubspot将使用传递给“authorization”URL上的的参数“code”来验证授权。然而，我不断地发现这个错误：

  string（171）{“status”：“BAD_GRANT_TYPE”，“message”：“缺少或未知的授予类型”，“correlationId”：“f0508752-24bc-40e4-b0bc-51e358459653”，“requestId”：“96044613D4E4A5AAB7356FAB0401E5C”}“

---

我有相同的错误响应，这似乎是一个编码问题
我与Postman进行了调试，发现以下代码有效：

<?php

$curl = curl_init();

curl_setopt_array($curl, array(
  CURLOPT_URL => "https://api.hubapi.com/oauth/v1/token",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 0,
  CURLOPT_FOLLOWLOCATION => true,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => "grant_type=authorization_code&code=string&redirect_uri=string&client_id=string&client_secret=string",
  CURLOPT_HTTPHEADER => array(
    "content-type: application/x-www-form-urlencoded",
    "Cookie: __cfduid=someidfrompostman"
  ),
));

$response = curl_exec($curl);

curl_close($curl);
echo $response;