Hi Jason
First create an ordinary account - click Login in the top right corner, then in the pop-up, click "Don't have an account?" or whatever and complete the details. These don't have to be the same as you use in the software or on the forum.
Once you have that, you can go to Options... Account (top left) and link your RadarBox with the account. You'll need your box number and its password.
HTH
Rod