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 support@dekunu.tech with your request.
Thanks