If you want patients to respond to reminders, such as to confirm or cancel their attendance, you need to enable two-way responses for SMS reminders.
Click Settings > Reminders.
Under the Preferences section, next to the group or practitioner name, click Edit.
Tick the checkbox for Two-way responses.
At the bottom of the pop-up, tick the checkbox if you want to disable reminders to all future-dated appointments, including those you have already scheduled
If your patients aren’t responding, give them a prompt! Edit your SMS reminder template for pre-appointment reminders to include instructions such as "Reply YES to confirm or call to reschedule."