https://help.openai.com/en/articles/7232945-how-can-i-use-the-chatgpt-api
contains this
Is fine-tuning available for the
gpt-3.5-turbo?Currently, we only support fine-tuning of our base models. Please review the fine-tuning guide for more details.
Which is now wrong and should reflect the ability to fine tune 3.5-turbo