how to view heroku port number for a given application?
I tried to use "heroku config:get PORT" command.but windows command prompt gave the result as " ! No app specified ". what should I do?
The port number is not per-application, but per-dyno. Only your dyno has that information.
And you don't need to get it externally either. No matter which port is set for that dyno, your app will always be available externally on port 80.