PayPal自适应支付使用访问令牌

我想从一个帐户到另一个帐户进行自适应支付。我可以得到一个访问令牌，但我不知道如何使用访问令牌进行支付API调用。其实我想绕过PayPal的登录界面。

    global $token;
     $url = 'https://api.sandbox.paypal.com/v1/AdaptivePayments/Pay';
     $createPacket = array(
        "actionType" => 'PAY',
        "currencyCode" => "SGD",
        "receiverList" => array(
            "receiver" => array(
                array(
                    "amount" => '34.00',
                    "email" => 'abc@gmail.com',
                )
            )
        ),
        "returnUrl" => $params['redirect_url'],
        "cancelUrl" => $params['cancel_url'],
        'senderEmail' =>'abcd@gmail.com',
        "requestEnvelope" => $this->envelope);
    $curl = curl_init($url);
    curl_setopt($curl, CURLOPT_POST, true);
    curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);
    curl_setopt($curl, CURLOPT_HEADER, false);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($curl, CURLOPT_HTTPHEADER, array(
        'Authorization: Bearer ' . $token,
        'Accept: application/json',
        'Content-Type: application/json'
    ));
    curl_setopt($curl, CURLOPT_POSTFIELDS,json_encode($createPacket) );
    #curl_setopt($curl, CURLOPT_VERBOSE, TRUE);
    $response = curl_exec($curl);

感谢您的帮助。