I can confirm that just putting nothing in the "Organization name/ID" on the OpenAI Settings page also works fine. So, in summary, using the Organizational causes the reported error on this install, but entering the Organizational ID or nothing, works fine.
Thank you for your assistance.
Thinking about this comment:
"Is the API key entered the API key, or the org id? Some have mixed these up."
I went to the OpenAI API "Organization settings" and copied the Organization ID (as opposed to the the Name) and pasted that into the "Organization name/ID" field at /admin/config/openai/settings
Tested the Prompt page again and it worked fine. Changed it back to the Organization name and it failed again. So, it seems that the Organization Name does not work on this install.
Thanks!
edwardmonk → created an issue.