Php 在获得ResponseToken和TokenSecret后处理Paypal付款

使用权限API获取reponseToken和TokenSecret后处理付款。下面是用于处理付款的代码。我已经用responseToken和TokenSecret创建了签名

    $apiCred_user = $user_id;
    $apiCred_pass = $passwd;
    $accessToken = 'h4TZXQ-YTSRU1v.3xkH29I536CulbrLtC52FX468BepI5PEI9uYasQ';
    $tokenSecret = 'boppIESaQJsdoSFjhjwjhfNHiiQ';
    $url1 = "https://api.sandbox.paypal.com/nvp";
    $auth = new AuthSignature();
    $response = $auth->genSign($apiCred_user,$apiCred_pass,$accessToken,$tokenSecret,'POST',$url1);

    $authString =
    "token=".$accessToken.
    ",signature=".$response['oauth_signature'].
    ",timestamp=".$response['oauth_timestamp'];

     $headers_arr = array(
        "X-PAYPAL-REQUEST-DATA-FORMAT:NV",
        "X-PP-AUTHORIZATION:".$authString,
        "X-PAYPAL-RESPONSE-DATA-FORMAT:json",
        "X-PAYPAL-APPLICATION-ID:APP-80W284485P519543T"
    );
$params = array(
        "METHOD"=> "DoDirectPayment",
        "PAYMENTACTION"=> "Sale",
        "AMT"=> "22.00",
        "ACCT"=> "4111111111111111",
        "CVV2"=> "111",
        "FIRSTNAME"=> "Jane",
        "LASTNAME"=> "Smith",
        "EXPDATE"=> "012018",
        "IPADDRESS"=> "127.0.0.1",
        "STREET"=> "123 Street Way",
        "CITY"=> "Englewood",
        "STATE"=> "CO",
        "ZIP"=> "80112",
        "VERSION"=> "86",
        "SIGNATURE"=> $signature,
        "USER"=> $user_id,
        "PWD"=> $passwd,
        "SUBJECT"=> "thirdparty@mail.com"
    );
    try{
$curl_session =  curl_init();
curl_setopt($curl_session, CURLOPT_URL,$url1);
curl_setopt($curl_session, CURLOPT_HTTPHEADER, $headers_arr);
curl_setopt($curl_session, CURLOPT_POST, 1);
curl_setopt($curl_session, CURLOPT_POSTFIELDS, http_build_query($params));
curl_setopt($curl_session, CURLOPT_CONNECTTIMEOUT,10); 
curl_setopt($curl_session, CURLOPT_TIMEOUT, 10);                
//curl_setopt($curl_session, CURLOPT_RETURNTRANSFER, 1);
//curl_setopt($curl_session, CURLOPT_FOLLOWLOCATION, 1);
curl_setopt($curl_session, CURLOPT_SSL_VERIFYPEER, 0);
$response = json_decode(curl_exec($curl_session));

我没有得到任何结果

我这样做对吗？处理付款