Substitutes can be shown as a teacher of record for a class by entering them as an instructor via the Schedule tab in the Class Detail page. Once in the Schedule tab, an administrator can click on Modify next to the class date. This will open a pop-up box where you can select an instructor as a substitute for that date. When attendance is taken on that date, the substitute teacher will be considered the teacher.
The teacher of record for the class can also record that a substitute was present on a given day directly from the Class Attendances page by selecting their name from the drop-down and checking the box marked Substitute Present. This will also automatically modify the instructor name on that class date in the Class Detail page Schedule Tab.
Substitutes, however, are not allowed to take attendance or access a class.
The best way for a substitute to take attendance is to print a sign-in sheet for the sub and then have the teacher record the attendance upon their return and note the Sub was present.
If the teacher is going to be absent for an extended period (long term substitute) or you have a team teaching class with multiple teachers, you should add the additional teachers to the class. Go to Class Details and click "I Want To = Manage Instructors and Sponsors". Add the additional teacher(s) here and those teachers will now have full access to the class. Please note that additional instructors are considered as a teacher for all the class dates and hours and will show as such on the Instructor Hours report.
WHY CAN'T SUBSTITUTES ACCESS A CLASS? Too much access! You probably want them to take attendance only. For the one day. But actually, they can do anything. So it just isn't a good idea.