avoidance of double bookings

Dear BookingPress team,

I offer various services, but this can only be carried out once at an available time.
How can I set that if, for example, service A was booked at 8 a.m., service B can no longer be booked at the same time.
Currently there have been occasional double bookings for an available time, I would like to avoid that.

Thank you for your support and have a nice day.

Best regards,
Frank