Google Classroom push notification registration Permission Denied for Students Only - google-api

Question

I'm trying to create a registration for push-notifications with Python googleapiclient for Google Classroom. My code is working for classes where the user is a teacher but is not working for when the user is a student in a given class. I've tried on gsuite and non gsuite accounts.
The error is googleapiclient.errors.HttpError: <HttpError 403 when requesting https://classroom.googleapis.com/v1/registrations?alt=json returned "The caller does not have permission">
The relevant code is
def register(self, courseId):
body = constants.registration_body(courseId)
o = self.service.registrations().create(body=body).execute()
return o["registrationId"], o["expiryTime"]
where self.service is build("classroom", "v1", credentials=get_creds(uid, db)).
and constants.registration_body returns
{
"feed": {
"feedType": "COURSE_WORK_CHANGES",
"courseWorkChangesInfo": {
"courseId": courseId,
},
},
"cloudPubsubTopic": {
"topicName": secret.pubSubTopicName,
},
}
I have also enabled all relevant API Scopes to remove that from troubleshooting:
scopes = [
"https://www.googleapis.com/auth/classroom.push-notifications",
"https://www.googleapis.com/auth/classroom.coursework.students.readonly",
"https://www.googleapis.com/auth/classroom.coursework.me.readonly",
"https://www.googleapis.com/auth/classroom.announcements.readonly",
"https://www.googleapis.com/auth/classroom.courses.readonly",
"https://www.googleapis.com/auth/classroom.courseworkmaterials.readonly",
"https://www.googleapis.com/auth/classroom.topics.readonly",
"openid",
]
I'm not sure if it is a code error since it works when users are teachers. Is this a limitation of the Google Classroom API?
Full code: https://github.com/karmanyaahm/google_classroom_discord_feed

Answer 1

This is intended behaviour:
Your code is fine, and this is working as intended. Push notifications are a tool to manage courses, not to be used by students, so it makes sense that only teachers and administrators can create registrations.
While not very explicit, the fact that a user needs to be a teacher in order to manage notifications is implied by the following statement, to be found in the official docs:
Your Cloud Pub/Sub topic only receives notifications about resources that you can view with the credentials you supply when creating a registration. For example, if the user revokes permission from your application or is removed as a teacher, notifications are longer delivered.
Reference:
Push notifications in the Classroom API