We invite you to read the article dedicated to the creation of a workflow by SMS
Activate the "Reservation reminder" from Admin> Personalization> Order then the General block :
Customize the time limit (in days) when the reminder will be sent
Attention for delays in hours, thank you for contacting support.
Create the dedicated Workflow with the event: "booking: reminder" :
Check "By SMS" and enter the ID of your template :
Leave the "by SMS to" field free