Can I disable the SMS notifications?

Yes. To do so, open Settings > Default settings > SMS templates and disable the default SMS template.

Important: This setting only takes effect if it is not overridden by an appointment template.

Therefore, also check each individual appointment template under Settings > Appointment templates:

1. Open the desired appointment template.
2. Switch to the SMS templates tab.
3. Make sure that “Default setting” is selected there.

If an individual SMS template is stored instead, SMS notifications will continue to be sent for this appointment template, even if the default SMS template has been disabled.