Follow these steps to successfully deploy your ExpressJS application on Heroku:

• Create a Heroku Account and Install Heroku CLI: Start by signing up for a Heroku account if you don't already have one. Then, install the Heroku Command Line Interface (CLI) on your computer.
• Prepare Your Application: Ensure your ExpressJS application is ready for deployment. Make sure to include a `package.json` file that lists your application's dependencies.
• Initialize Git Repository: If your application isn't already in a Git repository, initialize one with `git init`.
• Login to Heroku: Open your terminal and run `heroku login` to authenticate your Heroku account.
• Create a Heroku App: Run `heroku create` in your terminal. This will create a new Heroku app and add a remote named "heroku" to your Git repository.
• Configure the Port: In your ExpressJS application, ensure you're using the `process.env.PORT` variable to listen on the appropriate port Heroku assigns.
• Start Script: In your `package.json` file, add a start script that tells Heroku how to start your application.
• Commit Your Changes: Commit all your changes to Git by running `git add .` followed by `git commit -m "Initial Heroku deployment"`
• Deploy to Heroku: Push your changes to the Heroku remote by running `git push heroku master`.
• Open Your Application: After a successful deployment, run `heroku open` to open your application in your default web browser.