flask-wtf | Simple integration of Flask and WTForms , including CSRF | Frontend Framework library

Back to the error log itself, Flask-ReCaptcha has code like from jinja2 import Markup. But, since jinja2==3.1.0, Markup's position has changed. Try pip install jinja2==3.0.0`.

You will probably meet other problems as Flask-ReCaptcha is really old.

The only suggestion would seem to be the rather unpleasant forcing of the background image to nothing:

RECAPTCHA_ENABLED: Bool - True by default, when False it will bypass validation

Future calls to recaptcha.verify() in your flask server file will return True by default as a result.

To disable and hide the recaptcha in the HTML template code, simply omit any code with {{ recaptcha }} in your form.

Found from the documentation here: https://github.com/mardix/flask-recaptcha

While venv is activated and you're in project directory (where manage.py live), do the following:

• Open requirements.txt
• Delete unneeded modules from requirements.txt
• Uninstall unneeded modules with pip uninstall module
• Now run pip freeze requirements.txt
• Deactivate venv
• Then add requirements.txt to source control git add -A
• Commit your changes git commit -m "deleted unneeded modules"
• If you have existed Heroku app, connect to it with heroku git:remote -a myapp, else pass this step
• Deploy, git push heroku master

If you are unsure which modules your project need and I can't determin exactly the project's requirements but if you have basic project, you only need 3 modules which are Django, psycopg2-binary, gunicorn, so do the following for clean deploy:

• Delete venv
• Outside project directory, create new one
• Activate venv
• Install the modules you need, probably Django, psycopg2-binary, gunicorn
• Now run pip freeze requirements.txt
• Deactivate venv
• Then add requirements.txt to source control git add -A
• Commit your changes git commit -m "deleted unneeded modules"
• If you have existed Heroku app, connect to it with heroku git:remote -a myapp, else pass this step
• Deploy, git push heroku master

The summary is that eventlet (0.32.0) is currently not compatible with Python 3.10 because it tries to patch types that have become immutable in Python 3.10.

Like with your requirements, it is good practice to be more specific with your Docker dependencies too. Today using the tag 3 for the Python Docker image will give you 3.10.0, unless it is using a cache. In the future it could be a different version. Since there is a compatibility issue with Python 3.10, use Python 3.9 - the currently latest Python 3.9 Docker tag is 3.9.7.

i.e. it should work once you change your first line of the Dockerfile to: