node-scheduler to send response from node REST API - node.js

Question

I am working with node REST API. I need to send 2 different responses from single API. So I am sending first response from API as res.send(). Then I am using node-schedule to send remaining 1 response after some time using node-fetch.
But failing when using fetch from node-schedule. fetch is going to catch block directly.
require('dotenv').config();
const express = require('express');
const app = express();
const bodyParser = require('body-parser');
const schedule = require('node-schedule');
const rule = new schedule.RecurrenceRule();
rule.second = new schedule.Range(0,59,20);
const subscriptionRouter = express.Router();
const port = process.env.NODE_APP_PORT || 3000;
app.use(bodyParser.urlencoded({ extended: true }));
app.use(bodyParser.json());
app.use('/api', subscriptionRouter);
app.listen(port, () => {
console.log(`Running on port ${port}`);
});
var reqComing = {};
subscriptionRouter.route('/subscriptions')
.post((req, res) => {
reqComing = {...req.body};
let responseJSON = {};
// msgId will be having some random generated value
if(msgId ==""){
responseJSON.statusCode = 400;
responseJSON.statusDesc = "Bad Request";
responseJSON.msgId = msgId;
}
else{
responseJSON.statusCode = 200;
responseJSON.statusDesc = "Posted";
responseJSON.msgId = msgId;
}
res.send(responseJSON);
})
if(JSON.stringify(reqComing) === '{}'){
schedule.scheduleJob(rule,function(){
let objectToBeSent = {someData};
fetch('URl where to send response',
{
method: 'post',
body: JSON.stringify(objectToBeSent),
headers: {'Content-Type': 'application/json'}
})
.then(res => console.log(res.text()))
.catch(err => console.log("Error while sending response", err));
});
}