Fine tuning is not an effective way to add new content to a model. It’s useful for training models to produce output in different formats, or achieve higher performance in specific tasks (e.g. categorisation, content extraction), but it’s not possible to add content.
The best way to think about it is you can fine tune to teach a model new tricks, but not new facts. If you want to reduce hallucination or introduce new content then RAG is the way to go.