Force users to select a child forum to post

Posted by paulomogie.com on
URL: https://support.nabble.com/Force-users-to-select-a-child-forum-to-post-tp7604898.html

Members just click on that "New Topic" at the beginning of the forum without first clicking on a category first. Please how do I practically stop them from doing this. I read the article here but didn't show how to make only the parent forum read only. Please I need help. Thank you