Help with authentication?

[AllenDowney]

This tool looks super useful, so thanks!

I am just getting set up and I'm running into this error:

NotFoundError: litellm.NotFoundError: OpenAIException - Error code: 404 - {'error': {'message': 'The model 
`gpt-4-turbo` does not exist or you do not have access to it.', 'type': 'invalid_request_error', 'param': None, 
'code': 'model_not_found'}}

I have an environment variable with my OpenAI API key:

$ echo $OPENAI_API_KEY
sk-proj-etcetc

But I don't think the API key is working. I also tried creating a SimpleBot, and I am also getting authentication errors.

So I could use some help debugging. Is there a simple test I can use to check that my API key is working or figure out why it's not?