Heroku is deploying old react? - reactjs

Question

Im using laravel framework (as rest api) and reactjs (to render views). I did a lot of changes to my code (local) and then pushed it on github and deploy on heroku. I noticed that react app is rendering old code version when laravel api works fine (i can use routes which i added). Why react didnt update?
package.json:
{
"private": true,
"scripts": {
"dev": "npm run development",
"development": "cross-env NODE_ENV=development node_modules/webpack/bin/webpack.js --progress --hide-modules --config=node_modules/laravel-mix/setup/webpack.config.js",
"watch": "npm run development -- --watch",
"watch-poll": "npm run watch -- --watch-poll",
"hot": "cross-env NODE_ENV=development node_modules/webpack-dev-server/bin/webpack-dev-server.js --inline --hot --config=node_modules/laravel-mix/setup/webpack.config.js",
"prod": "npm run production",
"production": "cross-env NODE_ENV=production node_modules/webpack/bin/webpack.js --no-progress --hide-modules --config=node_modules/laravel-mix/setup/webpack.config.js"
},
"devDependencies": {},
"dependencies": {
"axios": "^0.18",
"babel-preset-react": "^6.23.0",
"cross-env": "^5.1",
"jquery": "^3.2",
"laravel-mix": "^2.0",
"lodash": "^4.17.4",
"popper.js": "^1.12",
"react": "^16.2.0",
"react-dom": "^16.2.0",
"gh-pages": "^2.0.1",
"react-icons": "^3.2.2",
"react-redux": "^5.0.7",
"react-scripts": "1.1.5",
"redux": "^4.0.0",
"styled-components": "^4.0.2",
"react-router-dom": "^4.3.1",
"redux-thunk": "^2.3.0"
}
}

Answer 1

May be the problem with your browser cache. Not in heroku. Please clear your browser cache and open your app again

Answer 2

Okay i figured it out! I need to render project on localhost to regenerate app.js in public/js before deploy on heroku -_-'