Deploying MERN to Heroku is failing - node.js

Question

I am trying to deploy this site to Heroku but it is giving me an error of deployment
here is my GitHub code: https://github.com/hazem-kamel/Guestbook-MERN
Logs:
Installing dependencies
Installing node modules (package.json + package-lock)
> nodemon#2.0.2 postinstall /tmp/build_d37d1bf6b721c463128a9d76ebc0c69a/node_modules/nodemon
> node bin/postinstall || exit 0
Love nodemon? You can now support the project via the open collective:
> https://opencollective.com/nodemon/donate
added 194 packages from 102 contributors and audited 195 packages in 4.934s
2 packages are looking for funding
run `npm fund` for details
found 2 low severity vulnerabilities
run `npm audit fix` to fix them, or `npm audit` for details
-----> Build
Running build
> Backend#1.0.0 build /tmp/build_d37d1bf6b721c463128a9d76ebc0c69a
> run-p build:**
sh: 1: run-p: not found
npm ERR! code ELIFECYCLE
npm ERR! syscall spawn
npm ERR! file sh
npm ERR! errno ENOENT
npm ERR! Backend#1.0.0 build: `run-p build:**`
npm ERR! spawn ENOENT
npm ERR!
npm ERR! Failed at the Backend#1.0.0 build script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
npm ERR! A complete log of this run can be found in:
npm ERR! /tmp/npmcache.AjLZ0/_logs/2020-05-24T20_24_12_312Z-debug.log
-----> Build failed
We're sorry this build is failing! You can troubleshoot common issues here:
https://devcenter.heroku.com/articles/troubleshooting-node-deploys
Some possible problems:
- Node version not specified in package.json
https://devcenter.heroku.com/articles/nodejs-support#specifying-a-node-js-version
Love,
Heroku
! Push rejected, failed to compile Node.js app.
! Push failed
I tried several codes but it is also failing : I am deploying by using GitHub code and Heroku automatic deploy

Answer 1

Install/add to your npm/yarn respectively: https://www.npmjs.com/package/npm-run-all
Also, preferred way while building a Heroku app is to delete the node_modules folder and only upload the package.json (that contains dependencies to be installed!). Heroku, while deploying your app automatically scans the package.json file and installs all the depenencies.