Is it possible to enter student attendance massively?

Certainly. You will simply need to navigate to the desired individual or group course and click the second Lesson Agenda icon.

Now from the next screen, click the top right Attendance Register button.

I will now be able to view the list of all lectures in that course, with the lecturer who supported it and all students enrolled.

Now, by placing the flag on the checkbox turn under the Lecture Time, it will be possible to enter attendance for all those enrolled in that course, for one or more sustained lessons, in a mass manner.

Click the Update Attendance button to finish the operation.