Once a Class In-charge starts a lecture using Acadly, every student is notified that the lecture has begun. There are two ways to record attendance:
Manual: The Class In-charge can do a manual roll call during the lecture to see which of the students are actually present at the venue. Using the same list, the Class In-charge can mark the students as "Present".
Automatic: Everything you need to know about automatic attendance is in a separate help section titled "Attendance". Please do go through it. You can also read about automatic (one-tap) attendance here.