我有一个服务帐户。
我写了一个PHP脚本来接收一个token：

<?php

require_once 'JWT_1.php';
require_once 'JWT_KEY_1.php';

use Firebase\JWT\JWT;
use Firebase\JWT\Key;

$privateKey = <<<EOD
-----BEGIN PRIVATE KEY-----
someKey
-----END PRIVATE KEY-----
EOD;

$publicKey = <<<EOD
-----BEGIN PUBLIC KEY-----
someKey
-----END PUBLIC KEY-----
EOD;

$payload = array(
  "iss" => "myName@name.iam.gserviceaccount.com",
  "scope" => "https://www.googleapis.com/auth/postmaster.readonly",
  "aud" => "https://oauth2.googleapis.com/token",
  "exp" => (time() + 600),
  "iat" => time()
);

$jwt = JWT::encode($payload, $privateKey, 'RS256');

$urlToken = 'https://oauth2.googleapis.com/token';
$url = 'https://gmailpostmastertools.googleapis.com/v1/domains';

$payloadToken = array(
  "grant_type" => "urn:ietf:params:oauth:grant-type:jwt-bearer",
  "assertion" => $jwt
);

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $urlToken);
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, $payloadToken);
// Timeout in seconds
curl_setopt($ch, CURLOPT_TIMEOUT, 30);
$tokenAnswer = json_decode(curl_exec($ch), true);
$token = $tokenAnswer['access_token'];
curl_close($ch);

$ch = curl_init();
$headers = array(
  'Authorization: Bearer ' . $token,
  'Accept: application/json'
);
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, 'GET');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_ENCODING , "");
// Timeout in seconds
curl_setopt($ch, CURLOPT_TIMEOUT, 30);
echo curl_exec($ch);

当尝试获取域列表https://gmailpostmastertools.googleapis.com/v1/domains时，响应是一个空数组。
与此同时，如果我对该方法进行测试检查，我会得到一个列表：https://i.imgur.com/XqgtnHV.png
有什么问题吗？