In the UpLaunch platform, if an appointment needs to be canceled, use the Appoointment Actions sidebar -> Cancel Appointment option.
When you cancel an appointment, the UpLaunch platform will send them an email asking them to reschedule their appointment.
Does it affect which campaign they are currently in?
No, whichever campaign they are currently in, they will continue on to the next step with no change to that campaign. If the contact is in the lead stage, the dynamic call to action at the bottom of most emails, will still ask for them to book an appointment.