无法从响应获取数据

Question

console.log（body）打印正确的结果，但是在使用时 body.payment_request.longurl，它显示TypeError：无法读取未定义的属性“ longurl”。

我正在尝试在流星项目中添加付款界面。

request.post('https://test.instamojo.com/api/1.1/payment-requests/', {form: payload,  headers: headers},  function(error, response, body){
        //console.log(body.success);
        if(!error && response.statusCode == 201){
            console.log(body);
            console.log(body.payment_request.longurl);

        }

      });

输出

{
     "success": true,
     "payment_request": {
         "id": "6d2d4f0d56984486a1b325a13db59678",
         "phone": "+919999999999",
         "email": "foo@example.com",
         "buyer_name": "John Doe",
         "amount": "2500.00",
         "purpose": "FIFA 16",
         "expires_at": null,
         "status": "Pending",
         "send_sms": true,
         "send_email": true,
         "sms_status": "Pending",
         "email_status": "Pending",
         "shorturl": null,
         "longurl": "https://test.instamojo.com/@rathore16696/6d2d4f0d56984486a1b325a13db59678",
         "redirect_url": "http://www.example.com/redirect/",
         "webhook": "http://www.example.com/webhook/",
         "allow_repeated_payments": false,
         "customer_id": null,
         "created_at": "2019-02-
         "modified_at": "2019-02-02T15
}

TypeError：无法读取未定义的属性'longurl'。