I have installed the application on my Nokia Lumia 630 Dual Sim and there was no way to register for an account. The only possibility related to this procedure is the PIN/Login menu where you enter the username, password, and the PIN ID. That's it. No registration form or button can be found on the software. You will have to acquire login credentials from your local supplier of pre-paid cards available for this service. There is no official website to acquire additional information.
However, I see on the main interface that the software attempts to Register, but I soon receive Invalid login which means my account is not good. Try switching the connection to WiFi or Data Connection and then try again.