Adding an aircraft, how to?

I would like to add the different aircraft that I have been jumping from but the Dekunu cloud apparently does not allow the end user the ability to add any aircraft of their choice. I do not see the logic in requiring a registration number and for Dekunu to offer a limited list of predesignated aircraft to choose from.
I am not impressed with this lack of functionality. I could find no help info relating to this option.
Maybe I am missing something obvious. If so, can someone please enlighten me?

@skytech73 The Dekunu Cloud is in beta, lots more functionality and user enhanced features will be coming soon including adding aircrafts etc.
In the meantime you can email with your request.