How to deploy a React App with an express API on Heroku. (MERN) stack

This video explains how you would deploy a MERN stack application(Express and React app). In this video we create a react app, and serve it from an express API to heroku(a plat form as a service). It is advised you have a basic knowledge about web apps like react although it is not a necessity.
This is basically how you deploy this kind of application during production.

[allanjohn]

bro every thing worked fine on my local host but when i edit or add new components in the app.js file in the react folder it does not reflect on the browser