To enter students who are missing in your lesson as absent, first click on the corresponding lesson in the timetable.

Then click in the window that opens on the right side under "Students" on the tile with the number of students:

A list opens with all students assigned to this course. Here you can mark someone as absent using the green slider:

In the next step, click on this button to mark all other students as present:

If a student leaves the class early, you can edit the already confirmed attendance at any time by pressing the green slider again. A window opens in which you can specify when the child left class:

If you have marked a student as absent, but who came too late, you can use the same method to process the registered absence. Click the gray slider that represents the student's absence.
A window opens in which you can specify when the student has arrived late for class: