como dice el título, estoy tratando de implementar un sitio web en Heroku por primera vez. Cambié todos los puertos a Process.env.PORT || 3001 (3001 es el predeterminado).

Recibo este error al ejecutar los registros de heroku logs --tail

También tengo un perfil con los siguientes datos en él

 web: node backend/index.js // server index.js is in backend folder

y aquí está mi archivo Package.json

 { "name": "marketapp", "version": "0.1.0", "private": true, "dependencies": { "@testing-library/jest-dom": "^5.16.3", "@testing-library/react": "^12.1.4", "@testing-library/user-event": "^13.5.0", "axios": "^0.26.1", "babel": "^6.23.0", "bootstrap": "^5.1.3", "cors": "^2.8.5", "mongoose": "^6.2.10", "node-cron": "^3.0.0", "puppeteer": "^13.5.1", "react": "^18.0.0", "react-bootstrap": "^2.2.3", "react-dom": "^18.0.0", "react-hot-loader": "^4.13.0", "react-router-dom": "^6.3.0", "react-scripts": "5.0.0", "web-vitals": "^2.1.4" }, "scripts": { "start": "react-scripts start", "build": "react-scripts build", "test": "react-scripts test", "eject": "react-scripts eject", "server": "node public/index.js", "dev": "concurrently \"npm run server\" \"npm run start\"" }, "eslintConfig": { "extends": [ "react-app", "react-app/jest" ] }, "browserslist": { "production": [ ">0.2%", "not dead", "not op_mini all" ], "development": [ "last 1 chrome version", "last 1 firefox version", "last 1 safari version" ] }, "devDependencies": { "concurrently": "^7.1.0", "netlify-cli": "^9.16.3", "nodemon": "^2.0.15" } }