I think it's good form to mention it as a little disclaimer, just so people don't take it the wrong day. Just write (this post was originally written by me but formatted and corrected with LLM since English is not my primary language).

From what I've seen, people generally do not like reading a generated content, but every time I've seen the author come back and say "I used it because it isn't my main language" the community always takes back the criticism. So I'd just be upfront about it and get ahead of it.

That was already added before this reply.