How to ensure a time slot can only be selected once?

Mexico Visa Appointment Slot booking appointment slot meaning A conventionally defined time interval in a schedule, typically for appointments time · availability · opening · slot · date · appointment · booking · entry appointment slot meaning slot for 1, 2 Applicants is : xx-02-2024 But when I proceed to Book an Appointment, there's no option at all All dates are grey block I

appointment slot google calendar I am using paid Google Workspace Instead of this, there is an appointment slots option I found