SlotBattle operator accounts are not self-service.
Accounts are created by someone who already operates your casino. Ask an owner or admin to add you from Access → Users, using the email address you want to sign in with.
You will not be sent a password. Once the account exists, sign in with Email a link on the sign-in screen and set a password from your profile.
Setting up a brand new casino? That is a Gamba operation — contact your account manager.