Note This article assumes you have [x] Allow customers to confirm appointments checked in your appointment reminders at Settings/Appointment Reminders.
Summary
This scenario appears when you have a first and second appointment reminder sent to your customers.
Key Points
Customers who confirm on first reminder
Update email template
The second reminder does not include a confirm button if the appointment was confirmed from the first email or from the customer portal.
The same is true for text reminders. If an appointment has already been confirmed the reminder will not include the Text/SMS Confirmation Text.
If customers are telling you there is no confirm button in their reminder email, update your 'click the green button' text at Settings/Appointment Reminders to something like this:
If you have not already confirmed your appointment, please scroll to the bottom of this email and click the green button to confirm your appointment. If you have confirmed your appointment there is no further action needed on your part.