If you don't already have an account (you're not registered) in Neostar, go to page neostar.com and click the icon in the right upper corner, and select Registration (see picture).
You can use your Facebook or Google email-address, Facebook, or Google account to register. Registration and creation of a user account are free of charge. When registering, enter all the required information to make your profile complete.
There is a difference between the registration of ordinary users (natural persons) and contract users (legal entities registered for the sale and/or service of vehicles).
Below is a graphical representation of the registration flow.