Make sure you have python 3.8 installed.

Created a virtualenv and install the required packages.

python -m venv .venv
source .venv/bin/activate
pip install -r bot/requirements.txt -r requirements-dev.txt

Activate your python venv and run the following commands

python bot/app.py

which will start a flask server on port 3000 and forwarding Slack traffic to the slack handlers.

ngrok http 3000

Then configure Slack app with the ngrok https endpoint: