Pass github action environmental variables to python

On my CircleCI's config.yml file, someone wrote a shell post (ie):

curl -X POST -H 'Header: header' \
  --url https://website/${{secrets.SECRET_TOKEN}} \
  --data '{"text": "Hello ${{ github.actor }}"}'

I have to replicate the same behavior using python and requests (this file will be executed by CI). I don't understand how to handle those variables--because they are not CI's env vars, instead they are github action environmental variables.

url = "https://website/${secrets.ROBBY_SLACK_ALERT_TOKEN_CODE_REVIEWS}"
data = {"text": Hello ${github_actor}
f = requests.post(url, headers=headers, json=data)

note: I left the header out in the example above.

I could pass the github var to a ci var, and then retrieve it with python--but not sure the proper syntax to use in the config.yml (ie):

 - env: ENVIRONMENT_VARIABLE_NAME: ${{ secrets.SECRET_TOKEN }}

Any help would be welcome.

Thx