When you want to add more patients to your target, you follow the same process as before when you created your first recall.
If you are uploading a patient list with some patients who are already included in the Recall, they will not be recognised by the system. If you already have a list of 10 patients live in Appt Recall, and you upload a list of 11, 10 of which are the same as those first 10, then only one patient will be added.