Reschedule visa appointment

Hi, I have a visa appointment, but I would like to reschedule it now. While trying to reschedule I received an error message. Do I need to cancel my current visa appointment and then reschedule, or can I just reschedule and the appointment will be updated?

Please advise.

Thank you!

I think you will need to cancel current appointment and book a new one.
Can VFS and double check.