Heroku python 'Application Error' ("An error occurred in the application and your page could not be served")

I have a python-based website I'm trying to upload through Heroku (not ideal I know but it's faster than learning JS). the python script is using flask, and when run locally it works fine. i uploaded it to heroku (git, commit etc) but when i try to open the app in the browser (not locally) i get the following message: "An error occurred in the application and your page could not be served. If you are the application owner, check your logs for details. You can do this from the Heroku CLI with the command" i checked the logs and i can't find anything wrong. please help I've been stuck on this for way too long and the heroku support hasn't been much help