Sets the number of people who actually attended the session for the given booking.
The setAttendance() function returns a Promise that resolves when attendance information has been updated.
The number of attendees can be greater than 1 when the booking is made for a group of people.
Set the attended boolean to true if the customer making the booking or anyone from their group attended.
Notes:
numberOfAttendees and attended.suppressAuth options to true.ID of the Booking to be updated.
Attendance information for the booking
An object representing the available options for setting attendance.