Flask app dont start on heroku server

Question

I\'m trying to deploy a Flask app with Heroku. It\'s simple API. Works great local with foreman but I get error (log is below) when starts on heroku.

This is my app code

Answer 1

1.Procfile should be without any extension.

2.Content of Procfile should be: web: gunicorn app:app --preload

Note:usually --preload is used when the size is more.