In the case that the Class Join Code for a class has been shared and you are seeing students appear in your Gradebook to be admitted that you don't recognize, then you will want to generate a new Class Join Code.
- From the Gradebook, click on the 3 dot menu
- Select "View Class Join Code"
- Click the Generate New Class Join Code button in the top right.
NOTE: Only new students trying to join will have to enter in the new Class Join Code. Existing students in the class will not have to do anything.