Initialize settings for express

app.js

const express = require('express');
const bodyParser = require('body-parser');

const app = express();

//middleware to allow the parsing of the incoming request body
app.use(bodyParser.json());

//Middleware to set response headers to handle CORS errors
app.use((req, res, next) => {
    res.set({
        'Access-Control-Allow-Origin': '*',
        'Access-Control-Allow-Methods': 'DELETE,GET,PATCH,POST,PUT',
        'Access-Control-Allow-Headers': 'Content-Type,Authorization'
    });

    next(); //pass control onto the next middleware
});