In Admin -> Permissions you'll see Asking questions. Set the combobox to Registered users with email confirmed. Then go to Admin -> Pages and tick the Ask a Question checkbox.
If an unregistered user tries to ask a question they will be displayed an error asking them to login or register.
Welcome to the Q&A site for Question2Answer.
If you have a question about Q2A, please ask 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.