I haven’t used anon mode. When that is enabled on the site does it add category permission option?
@moin with the adding of the anon group. Could category permission be set for that category that only Anon group can create/reply?
If so the Field in category settings to display when you can’t post there could give info and even a link for anon mode. I use this for when you need to be in a group to post there with a request join link to said group in my use case.
If this can work if the reply button is hidden with CSS it would need to unhidden for the can’t post pop up.