Udacity decided this project won't be upgraded to Python 3. This was not a deal breaker since using Anaconda one can have multiple environments running on the same computer.
Unfortunately, Apple latest OS (Big Sur) breaks Python 2 on Anaconda and since Python 2 is deprecated there won't be a fix for this.
I decided to migrate the project myself and include an Anaconda Environment file, I consider the environment should have been part of the course from the start.
You can create an environment using anaconda:
$ conda env create environments/python-3.8.yaml
$ conda activate py38
I offer no guarantees that will work or will be accepted by reviewers.
If you find it useful and feel like buying me a coffee, the link is below.