Struggling with MERN app deployment

I’ve been more than 20 hours combined trying to deploy this application with no success. The app runs perfectly with “heroku local” in the terminal. But when I deploy, it says the deployment was succesfull but when I go to the website, I get the following: Not found.

When I do “heroku logs”, the following error appears repeatedly:
Error: ENOENT: no such file or directory, stat ‘/app/client/build/index.html’

I know this means it can’t find the build folder, but I don’t know why. The commands in the package.json are the following:

{
  "name": "teachers-likelyhood",
  "version": "1.0.0",
  "description": "Cool rating website",
  "main": "server.js",
  "engine": {
    "node": "12.13.0",
    "npm": "6.14.5"
  },
  "dependencies": {
    "axios": "^0.20.0",
    "bower": "^1.8.8",
    "cors": "^2.8.5",
    "express": "^4.17.1",
    "config": "^3.3.1",
    "grunt": "^1.3.0",
    "express-validator": "^6.6.1",
    "mongoose": "^5.10.3",
    "nodemon": "^2.0.4"
  },
  "devDependencies": {},
  "scripts": {
    "start": "node server.js",
    "heroku-postbuild": "cd client && npm install && npm run build"
  },
  "author": "Guillermo",
  "license": "ISC"
}

Here the entire project repo:

and PLEASE HELP: I’ve been stuck for days.

Hello!

For me it worked fine: https://guillevazq-mern.herokuapp.com/.

What I didn’t do is use the heroku CLI. Instead I deployed directly from github: https://github.com/skaparate/MERN-Deployment-Help/, without modifying anything other than moving all the contents of project-rating to the root.

Try deploying directly from github and see if that works.

I have a similar problem a few months ago. I will suggest you l to install a dotenv package in order to use the environment path.

npm install dotenv