Followed all the steps to deploy Flask application. The app works fine on the localhost with no issues or errors. I added requirments.txt runtime.txt and Procfile. I runtime.txt I typed python "python-3.9.0". Procfile: "web: gunicorn app:app". And requiements.txt has these packages:
click==7.1.2
Flask==1.1.2
flask-heroku==0.1.9
gunicorn==20.0.4
itsdangerous==1.1.0
Jinja2==2.11.2
MarkupSafe==1.1.1
Werkzeug==1.0.1
When I push it to heroku this is the error I get:
Documentation on Heroku website is not really helpful. I don't have any clue what specifically can cause issues.