cPanel: open MySQL® Database Wizard, create a database and user, and give the user ALL PRIVILEGES. cPanel puts your account name in front, e.g. myuser_accounts. Plesk / DirectAdmin / VPS work the same way.
myuser_accounts
localhost
Moving from another system? Set "First invoice number" to carry on your numbering. Everything here can be changed later in Settings.
Accounts & Invoicing v1.0.0