使用paypal并行付款和PHP的无效请求

Question

我在youtube上关于使用php进行并行付款的教程。 问题是我一直收到无效的requset错误 这是我的代码的摘录：

$createtePacket = array(
        "actionType" => "PAY",
        "currencyCode" => "USD",
        "receiverList" => array(
            "receiver" => array(
            array("amount"=>"1.00" ,"email" => "mail@mail.com"),
            array("amount"=>"50.00" ,"email" => "mail2@mail.com"),

    )
    ),
        "returnUrl"=>"http://local.dev/store",
        "cancelUrl"=>"http://local.dev/store" ,
    "requestEnvelope" => array("errorLanguage"=>"en_US","detailLevel"=>"ReturnAll")

    );

，结果的错误部分是：

 message":"Invalid request: {0}

我在这里做错了什么想法？