Hi!
You probably did see this remark in the first link you posted:
function_callandfunctionshave been deprecated in favor oftools, however, the fine-tuning API still requires the legacy format at this time.
So you should be able to use the old instructions to validate the file:
https://platform.openai.com/docs/guides/fine-tuning/fine-tuning-examples
I am not sure how often the cheat-sheet is being updated. Following the docs is likely the safer route.