How did you get the warning popup implemented for identification questions when user asks a question? We want a similar thing for autograph identification questions on Sports SE.
This meta post doesn't seem to mention it.
There are actually two different popups (both existed even before banning identification questions, just that they were both warnings, now one is an error).
Both those things however are things that even the per-site moderators cannot add (or update) on their own. They have to be implemented by SE employees. However, as with all such things the usual way to get them implemented is issuing a
feature-request on the respective site's meta, gathering some traction for it and fleshing out the details, and then getting the local mods to ask SE to put it into action.