check your logs , there might be a error due to some file not being installed properly or
something import error. Just check your complete logs.
or you can create a text file of those and upload the same github link above , so that i am able to check it.
change your Procfile content to
web: gunicorn app:app
python3 is not valid dyno for heroku.
and also , change your runtime.txt from python 3.8 to python 3.7.2
it works now thankyou
No problem @adirayer.
If your doubt is resolved , i would request you to kindly mark this doubt as resolved and also to provide your valuable feedback as it helps us to provide you with better learning experience.
Thank You and Happy Learning 
.
I am also getting the same error hero log–tail
Hey @Vishal1072 ,
kindly raise a new doubt and share the screenshot of the error there.
Its already been a quite big this one.