firebase callable node function - node.js

Question

I try to use a node function in firebase callable function and wehn I try to use it as described I see this warning on VS code. any help? on what I can do
module "c:/Users/firat/Desktop/vuedg3/functions/node_modules/iyzipay/lib/Iyzipay"
Could not find a declaration file for module 'iyzipay'. 'c:/Users/firat/Desktop/vuedg3/functions/node_modules/iyzipay/lib/Iyzipay.js' implicitly has an 'any' type.
Try npm install #types/iyzipay if it exists or add a new declaration (.d.ts) file containing declare module 'iyzipay';ts(7016)
and this callable function return null when I try and call it from web app
this is my entire code
exports.trypay = functions.https.onCall((data, context) => {
var Iyzipay = require('iyzipay');
var iyzipay = new Iyzipay({
apiKey: "sandbox-11",
secretKey: "sandbox-11",
uri: 'https://sandbox-api.iyzipay.com'
});
var request = {
locale: Iyzipay.LOCALE.TR,
conversationId: '123456789',
price: '1',
paidPrice: '1.2',
currency: Iyzipay.CURRENCY.TRY,
installment: '1',
basketId: 'B67832',
paymentChannel: Iyzipay.PAYMENT_CHANNEL.WEB,
paymentGroup: Iyzipay.PAYMENT_GROUP.LISTING,
paymentCard: {
cardHolderName: 'John Doe',
cardNumber: '5528790000000008',
expireMonth: '12',
expireYear: '2030',
cvc: '123',
registerCard: '0'
},
buyer: {
id: 'BY789',
name: 'John',
surname: 'Doe',
gsmNumber: '[phone]',
email: 'email#email.com',
identityNumber: '74300864791',
lastLoginDate: '2015-10-05 12:43:35',
registrationDate: '2013-04-21 15:12:09',
registrationAddress: 'Nidakule Göztepe, Merdivenköy Mah. Bora Sok. No:1',
ip: '85.34.78.112',
city: 'Istanbul',
country: 'Turkey',
zipCode: '34732'
},
shippingAddress: {
contactName: 'Jane Doe',
city: 'Istanbul',
country: 'Turkey',
address: 'Nidakule Göztepe, Merdivenköy Mah. Bora Sok. No:1',
zipCode: '34742'
},
billingAddress: {
contactName: 'Jane Doe',
city: 'Istanbul',
country: 'Turkey',
address: 'Nidakule Göztepe, Merdivenköy Mah. Bora Sok. No:1',
zipCode: '34742'
},
basketItems: [
{
id: 'BI101',
name: 'Binocular',
category1: 'Collectibles',
category2: 'Accessories',
itemType: Iyzipay.BASKET_ITEM_TYPE.PHYSICAL,
price: '0.3'
},
{
id: 'BI102',
name: 'Game code',
category1: 'Game',
category2: 'Online Game Items',
itemType: Iyzipay.BASKET_ITEM_TYPE.VIRTUAL,
price: '0.5'
},
{
id: 'BI103',
name: 'Usb',
category1: 'Electronics',
category2: 'Usb / Cable',
itemType: Iyzipay.BASKET_ITEM_TYPE.PHYSICAL,
price: '0.2'
}
]
};
iyzipay.payment.create(request, function (err, result) {
return('result:'+result + 'error:'+err);
});
})