Angularjs PayPal自适应生成错误响应确认失败

使用PayPalaAdaptive时出现以下错误。 这些都是我所知道的关于错误的细节。 错误：响应确认失败。查看响应以了解更多信息。 在收到消息时。（D:\Qhoppaypal1\node\u模块\paypal自适应\

 app.post('/api/pay_for_palns_credit_card', function(req, res) {
     console.log(req.body);
     db = req.db;

     var email = 'admin@qhop.com';
     var amount = req.body.amount;
     var firstname = req.body.firstname;
     var lastname = req.body.lastname;
     var cardtype = req.body.cardtype;
     var cardnumber = req.body.cardnumber;
     var expiremonth = req.body.expiremonth;
     var expireyear = req.body.expireyear;
     var cvv = req.body.cvv;
     var payer = req.body.email;
     var collection = db.get('paymentscollections');
     var Paypal = require('paypal-adaptive');
     var paypalSdk = new Paypal({
         userId: 'id',
         password: 'password',
         signature: 'signatures',
         sandbox: true //defaults to false 
     });
     var payload = {
         requestEnvelope: {
             errorLanguage: 'en_US'
         },
         actionType: 'PAY',
         currencyCode: 'USD',
         feesPayer: payer,
         memo: 'this is a test',
         cancelUrl: 'http://test.com/cancel',
         returnUrl: 'http://test.com/success',
         receiverList: {
             receiver: [{
                 email: email,
                 amount: amount,
                 primary: 'false'
             }]
         }
     };

     paypalSdk.pay(payload, function(err, response) {
         console.log(payload);
         if (err) {
             console.log('in here');
             console.log(err);
             res.send(err);
         } else {
             collection.insert({
                 payload
             }, function(err, doc) {
                 if (err) {
                     console.log(err);
                     // If it failed, return error
                     res.send(err);
                 } else {
                     console.log(doc);
                     res.send(doc);
                 }
             });
         }
     });

 });