Check flask-combo-jsonapi as alternative rest json:api framework
The current framework that we use so far, doesn"t seem to be maintained any more. There is an alternative that has also an pypi entry, so we can install it via pip.
https://github.com/AdCombo/flask-combo-jsonapi
So the very easy question is if we can replace it in our backend & have a version that runs with more up to date versions of Flask.