In the app, the ? at the top right has the short form, and every word on the page opens its explanation.
Write to us at support@kaikusdr.example. Say which computer and receiver you have, and what the app said. The app's log files are under Settings › About; if the app ended with an error, it offers the report on the next start, and that is the most useful thing to send.
Your licence: get it again from your receipt's transaction number.