Anita,
Thanks for your question. Any registered user can add an idea. The Actions menu for the module will show the "Post Idea" action once a registered user is logged in. You may also create a link anywhere else on your site directly to the Post Idea URL. In the current version, non-registered users cannot add ideas.
Obviously, if you would like to suggest an idea, you may do so on our website under Community -> Idea Exchange.
Let me know if you have any other questions.
Thank you.