The code is present in attendance_portal directory. You should be well versed with django to contribute to this code.
- attendance_portal/accounts - this directory stores the code for all types of authentication (teacher, student, login, signup, logout).
- attendance_portal/attendance - this stores all the code for different functionalities for students and teachers. Rest files are pretty standard for any django project.
Go to installation instructions and follow the instructions to get the code working. If you add any new package update requirements.txt. Make a pull request with your changes. Also you can report any issue if any and propose new features. All the functions are properly commented so its not very difficult to find what any piece of code is doing.