Thanks both.
Richard, I think your request is for topics, not posts.
Rafael has the right base, but I don’t think you can order by created date (I hope I’m wrong?).
And if you could, I don’t believe IDs are assigned to posts based on when they are created.
Anecdotally in our Discourse instance, we are seeing many examples of IDs being assigned to posts outside of their chronological order.
This becomes an issue when you try to pull all posts using the method discussed here. If we can’t order posts by ID then it becomes impossible.