The error message clearly shows that the API key provided is incorrect. You should double check that you’ve correctly set up the environment variable OPENAI_API_KEY in your terminal.
Make sure that you’ve copied the API key accurately and that there are no extra spaces or characters and verify that the API key hasn’t expired and that it has the necessary permissions to access the OpenAI service.
Once you’ve confirmed that the API key is correct, try running the rasa train command again. If the issue persists, you may need to troubleshoot further by checking the API key’s permissions and verifying the endpoint configuration in your config.yml file.