Go to the Settings tab and scroll down to the Appointment Reminders. This is found under the Calendar section.
Click the + button to open and add a new row. From here, you can set up as many appointment reminders as you need.
From here, you can choose which appointment category the reminder is for and the SMS template you'd like to schedule.
You can also select how many days prior to the appointment date you'd like the patient to be notified.
For important appointments, multiple reminders can be set for the appointment category.
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