Firebase的云函數-getaddrinfo ENOTFOUND嘗試向Paypal的API發出請求PayPal-Node-SDKexports.requestPayment = functions.https.onRequest((req, res) => {     return new Promise(function (fullfilled, rejected) {         paypal.payment.create(create_payment_json, {}, function (error, payment) {             if (error) {                 rejected(error);             } else {                 console.log("Create Payment Response");                 console.log(payment);                 res.status(200).send(JSON.stringify({                     paymentID: payment.id                })).end();                 fullfilled(payment);             }         });      });});但我經常會犯一個錯誤：Error: getaddrinfo ENOTFOUND api.sandbox.paypal.com api.sandbox.paypal.com:443     at errnoException (dns.js:28:10)     at GetAddrInfoReqWrap.onlookup [as oncomplete] (dns.js:76:26)我嘗試過的事情：向完全不同的主機提出請求ENOTFOUND將請求包裝為cors(req,res, ()=>{...})預演https://寄給主人有什么問題嗎？