What will be Procfile for node+Angular 2 application?

I have an Angular 2 application. I want to deploy it to the Heroku. So it requires a Procfile. For my Node.js application, into Procfile I used

node serverName.js

But in the Angular 2 application I can not figure out what I should put down in Procfile to deploy this application to Heroku. Here's my application Weather Application

via B M Shams Nahid