You should first add your OpenAI secret key to an environment variable, for example:
export OPENAI_API_KEY=<your key here>
Then, in order to run the application, it is recommended for you to create a virtual environment by issuing the following commands:
python3 -m venv venv
source venv/bin/activate
Then, you should install the dependencies of the project with:
pip install -r requirements.txt
Finally, you can start the development application server with:
python backend.py