1. Add a Procfile

add a Procfile to the top of the Masonite project.

my Procfile is

web: gunicorn wsgi  --log-file -

add and commit

2. make a new app in Heroku

$ heroku create

3. add git remote

$ heroku git:remote -a {app-name}

4. Push on line

$ git push heroku master

For more information see this