When you first connect to a robot that’s not yet registered, a screen will pop up to guide you through the process.
You'll first need select your role, as only teachers are allowed to go through that process.
You'll need to provide your email and your school's name.
You can even add several robots in one go. Just switch on all the robots you want to register, connect to each one, and follow the steps on the screen. The robot serial number is automatically recorded when you connect.