Instructors and staff can find your studio on the Klasly sign-up page and ask to join. You add them from the Dashboard in one tap.
On the Klasly sign-up page, an instructor picks "I teach or work at a studio", types part of your studio name, taps it, and leaves their name and email.
A card appears at the top of your Dashboard: "<name> wants to join as staff", with their email. You also get a short email saying a request is waiting.
Press Add as instructor. It does exactly what Instructors → Invite does: they get an email with a link to set their password, and they are in. Ignore removes the card and sends nothing.