Why am I receiving a 403 Error when using Google Classroom API's StudentSubmissions.turnIn()?

Question

I give students google forms with their homework and when they submit the form, I'd like it to update the homework on Classroom to "turned in." But, I'm running into this error. I have all the correct courseId, courseWorkId, and student submission Id.

The program is the same program that created the assignment, so I shouldn't be having any issues with Developer Console authentication. I'm thinking that it's due to this (from the documentation):

"This may only be called by the student that owns the specified student submission."

Does this mean I somehow need to get permissions from the student to turn in their own homework?

Here's the line of code in question:

response = subs.turnIn({},courseId,courseWorkId,response.studentSubmissions[0].id);

This is the error:

GoogleJsonResponseException: API call to classroom.courses.courseWork.studentSubmissions.turnIn failed with error: The caller does not have permission
at handleFormSubmit(makeHomeworkForm:195:62)

Answer 1

Unfortunately for your use case, this is the expected behavior.

"This may only be called by the student that owns the specified student submission."

Does this mean I somehow need to get permissions from the student to turn in their own homework?

Not quite. It means the students credentials are required to turn in their work via the API. I think this feature request describes the behavior you're looking for. And you already noted the restriction that "the program [must be] the same program that created the assignment"; there's another feature request to have that requirement relaxed as well.

I would encourage you to upvote these requests if you are affected.