There is a setting in admin/categories that controls whether you need to get to the lowest level category or if you can post in any category of the hierarchy. Look for the Allow questions with a category but no sub-category setting.
Welcome to the Q&A site for Question2Answer.
If you have a question about Q2A, please ask here, in English.
To report a bug, please create a new issue on Github or ask a question here with the bug tag.
If you just want to try Q2A, please use the demo site.
April 20, 2021: Q2A 1.8.6 released!