You know, Forma has got 7 level users.
Administrator, Instructor, Mentor, Tutor, Student, Ghost, Guest
How to enter, the ghost and the guest users in Courses?
And, how the visitors can see course without a member of the LMS?
The 7 levels only refer to enrollment level in the course.
When you subscribe users to a course, you can choose their level either in the dropdown menu or in the last step of the wizard you use for massive subscriptions.
Ghost and guest level have slight differences between them.
That said: even if you are a guest student, you still have to be logged in into the Lms to see the course. That's an intentional architectural choice, and it's a logical consequence of the fact you have the 2 concepts of user level in the Lms and user level in the course.