cURL没有得到适当的回应

Question

我正在尝试使用我的PayPal API凭据获取访问令牌，这是代码

<?php

class PayPalAPI
{

    private $sandbox = true;
    private $url;
    private $clientid;
    private $secret;

    private $data;

    public function __construct($sbox = true)
    {
        $this->url['sandbox'] = "https://api.sandbox.paypal.com";
        $this->url['live'] = "https://api.paypal.com";
        $this->clientid['sandbox'] = "secretsandboxclientid";
        $this->clientid['live'] = "secretliveclientid";
        $this->secret['sandbox'] = "secretsandboxkey";
        $this->secret['live'] = "secretlivekey";

        $this->sandbox = $sbox;

        if ($this->sandbox == true)
        {
            $this->url['use'] = $this->url['sandbox'];
            $this->clientid['use'] = $this->clientid['sandbox'];
            $this->secret['use'] = $this->secret['sandbox'];
        }
        else
        {
            $this->url['use'] = $this->url['live'];
            $this->clientid['use'] = $this->clientid['live'];
            $this->secret['use'] = $this->secret['live'];
        }
    }

    public function getAccessToken()
    {
        $ch = curl_init($this->url['use'] + "/v1/oauth2/token");

        curl_setopt($ch, CURLOPT_ENCODING, "Accept: application/json");
        curl_setopt($ch, CURLOPT_ENCODING, "Accept-Language: en_US");
        curl_setopt($ch, CURLOPT_USERPWD, $this->clientid['use'] . ":" . $this->secret['use']);
        curl_setopt($ch, CURLOPT_POSTFIELDS, "grant_type=client_credentials");
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

        $response = curl_exec($ch);
        curl_close($ch);
        return $response;
    }
}

$api = new PayPalAPI();
$token = $api->getAccessToken();

var_dump($token);

?>

但是回应并不像预期的那样，出于某种原因，它正在倾倒神父＃34;这是一个很酷的未来＆＃34;

以下是链接http://xlagmasterx.com/test.php

为什么这会返回页面？