It can vary between courses if attendance is mandatory or not, so it is best to read thoroughly about each course in the Course Catalogue. The syllabus for each course can be found in Canvas. The syllabus should include information on reading materials and course assessment as well as stating if attendance is mandatory or in some way part of the course assessment.
The main rule is that attendance is not mandatory. Your grade may however partially depend on participation in discussions in class. If a course has mandatory attendance it is stated in the programme structure in the Course Catalogue as well as in the course description.
What if I miss class due to illness?
If it is a course with mandatory attendance you should contact the course instructor. The instructor's name and contact information can be found in Canvas. Poor attendance can lead to you losing the right to take examinations.
What if I am sick and miss an examination?
Please see the page on Makeup exams if it was a final exam.
For mid-term exams faculties may require that you turn in a doctor's note, in which case you would turn it in to the instructor or faculty office.