Keep getting pending request when trying to call endpoint, what's wrong? - node.js

Question

I have made an endpoint to get token for paytm payment integration. In backend when i'm calling api i'm getting reqdata json but in frontend when i'm logging await transactionAPI, i'm getting only pending promise. i've tried using then in backend in PaytmChecksum.generateSignature method & in frontend in fetch but nothing is working. Keep getting the same result. Pls help.
Frontend code:
const makePayment = async () => {
const data = {
oid: String(new Date().valueOf()),
amount: '1.00',
email: 'abc#gmail.com',
};
let transactionAPI = fetch('http://localhost:3000/api/pretransact', {
method: 'POST',
headers: {
'Content-Type': 'application/json',
},
body: JSON.stringify(data),
});
console.log(await transactionAPI);
}
Backend code:
const https = require('https');
const PaytmChecksum = require('./PaytmChecksum');
export default async function handler(req, res) {
if (req.method == 'POST') {
const { oid, amount, email } = req.body;
let mid = process.env.PAYTM_MID;
let paytmParams = {};
paytmParams.body = {
requestType: 'Payment',
mid,
websiteName: process.env.WEBSITE,
orderId: oid,
callbackUrl: 'http://localhost:3000/api/callback',
txnAmount: {
value: amount,
currency: 'INR',
},
userInfo: {
custId: email,
},
};
const checksum = await PaytmChecksum.generateSignature(
JSON.stringify(paytmParams.body),
process.env.MERCHANT_KEY
);
paytmParams.head = {
signature: checksum,
};
var post_data = JSON.stringify(paytmParams);
const requestAsync = () => {
return new Promise((resolve, reject) => {
var options = {
hostname: 'securegw-stage.paytm.in',
// hostname: 'securegw.paytm.in',
port: 443,
path: `/theia/api/v1/initiateTransaction?mid=${mid}&orderId=${oid}`,
method: 'POST',
headers: {
'Content-Type': 'application/json',
'Content-Length': post_data.length,
},
};
var response = '';
var post_req = https.request(options, function (post_res) {
post_res.on('data', function (chunk) {
response += chunk;
});
post_res.on('end', function () {
resolve(response);
});
});
post_req.write(post_data);
post_req.end();
});
};
const reqdata = await requestAsync();
res.send(200).json(reqdata);
}
}