So I have a full stack website and the frond end is hosted on netlify via github and the backend is hosted on heroku. When I make changes on front end I have to push each change to github in order to see the result. I am a newbie and I do not know how should I work on a project locally when all my routes are netlify and heroku routes.

This is the code

const express = require("express");
const path = require("path");
const mongoose = require("mongoose");
const dotenv = require("dotenv");
const cookieParser = require("cookie-parser");
const cors = require("cors");
const User = require("./models/userModel");

dotenv.config();



// set up server

const app = express();

app.listen(process.env.PORT || 5000, () =>
  console.log(`Server started on port: ${process.env.PORT || 5000 }`)
);

app.get("/test", (req, res) => {
  res.send("It works");
});

app.use(express.json());
app.use(cookieParser());
app.use(
  cors({
    origin: "https://awesome-murdock-.netlify.app/",
  

    
    credentials: true,
  })
);

// connect to mongoDB

mongoose.connect(
  process.env.MONGODB_URI,
  {
    useNewUrlParser: true,
    useUnifiedTopology: true,
  },
  (err) => {
    if (err) return console.error(err);
    console.log("Connected to MongoDB");
  }
);

// sign
// set up routes

app.use("/auth", require("./routers/userRouter"));
app.use("/customer", require("./routers/customerRouter"));



app.get('/', (req, res) => {
  res.send('Hi')
})

as you can see cors is ponting to my netlify app and it has not connection with my back end and the same is with backend