Clone an existing heroku app, and update and push again

Clone the app from Heroku:

Firstly open a terminal locally, and then type the following code to login Heroku...
heroku login

After login, clone the heroku app by typing the following code...
heroku git:clone -a myapp

If you are working with MERN app, then install NPM packages in frontend and backend. Edit the code as you would like.

 

Push the app to Heroku:

After editing, push the code into horoku by following steps...
Steps 1:
git add .

Step 2:
git commit -m "commit message"

Step 3:
heroku git:remote -a heroku app name

Step 4:
git push


It will take some moments to complete the load. After that check the website in the browser.