If you've added care professionals to your favourites, Florence can automatically send invitations to them when you post a shift.
This will give them the option to instantly book the shift. This happens if you select the 'send invitations to favourite and recommended workers' toggle, found on the shift posting page. (This option is turned on by default to help you fill shifts more easily.)
If you de-select this when posting future shifts, you'll always have the option of approving a worker before they're selected to work a shift.