Flask App with Database failing deploy beacuse of buildpack

I’m trying to deploy a flask app with a database but get this error after the requirements.txt is installed

[2022-07-17 08:16:12] yaml: line 3: mapping values are not allowed in this context
[2022-07-17 08:16:12] ERROR: failed to build: exit status 3
[2022-07-17 08:16:17] 
[2022-07-17 08:16:17] For documentation on the buildpacks used to build your app, please see:
[2022-07-17 08:16:17] 
[2022-07-17 08:16:17]    Python  v0.211.4  https://do.co/apps-buildpack-python

My procfile is

release:python manage.py db migrate; python manage.py db upgrade;
web: gunicorn --worker-tmp-dir /dev/shm app.wsgi

My runtime.txt is

python-3.9.6