How do I create an assignment shell in an assignment group?
Assignment shells are placeholders for Assignments that only include the assignment type, name, due date, and point value. You can choose to save the assignment as an unpublished assignment and edit the Assignment details later.
Assignment shells can be created in an assignment group in the Assignments index page. New courses include one assignment group by default. If you want to add your assignments to another assignment group, you must add assignment groups before creating an assignment shell.
Set the Assignment type by selecting the type drop-down menu , enter the Assignment title in the Name field , click the Calendar icon to select a due date  or manually enter a due date, and enter the number of points for the assignment in the points field .
If your institution has enabled a student information system (SIS) integration, you can enable the assignment to sync to the SIS by selecting the Sync to SIS checkbox .
To edit the assignment details, click the More Options button .
If you want to save your assignment shell and edit the details later, click the Save button .
Due dates are verified against course data. If you have set a due date that is not allowed, Canvas displays information about the error.
Correct the date and then save the assignment again.
Note: If the error relates to a course end date, and the course does not include specified course start and end dates, Canvas validates the assignment against the term date for the course.