I am unable to use npm start as it is giving `clean exit - waiting for changes before restart`. What should I do to remove the error
The output should be "port is running at 5000"

```
 (base) parthsharma@Parths-MacBook-Air server % npm start 

> server@1.0.0 start /Users/parthsharma/Desktop/Recollection_project/server
> nodemon index.js

[nodemon] 2.0.7

[nodemon] to restart at any time, enter `rs`

[nodemon] watching path(s): *.*

[nodemon] watching extensions: js,mjs,json

[nodemon] starting `node index.js`

[nodemon] clean exit - waiting for changes before restart

^C%   

(base) parthsharma@Parths-MacBook-Air server % nodemon index.js

zsh: command not found: nodemon

^C%                                                                            
(base) parthsharma@Parths-MacBook-Air server % 
(base) parthsharma@Parths-MacBook-Air server %  nodemon -w ./ 
zsh: command not found: nodemon
(base) parthsharma@Parths-MacBook-Air server % 

```

**Index.js:**

```
import express from 'express';
import bodyParser from 'body-parser';
import mongoose from 'mongoose';
import cors from 'cors';

const app = express();

app.use(express.json({ limit: "30 mb", extended: true }));
app.use(express.urlencoded({ limit: "30 mb", extended: true }));
app.use(cors());

const CONNECTION_URL = 'mongodb+srv://parthsharma:Pssword@cluster0.fuw21.mongodb.net/myFirstDatabase?retryWrites=true&w=majority';
const PORT = process.env.PORT || 5000;

mongoose.connect(CONNECTION_URL, { useNewUrlParser: true, useUnifiedTopology: true })
    .then(() => app.listen(PORT, () => console.log('Server running on port: ${PORT}')))
    .catch((error) => console.log(error.message));

mongoose.set('useFindAndModify', false);

```