If you are permitted to add students to your course this is how you proceed:
- From the course administration block click more first and then users/enrolled users.
- Click enroll users button.
- Search by email address for the user you would like to enroll.
- Make sure the correct role appears at the drop-down at the top.
- Click enroll button and finish enrolling users.
The user will now be enrolled in the role you selected in your course.