LearnCube has two different role permissions for teachers.
Teacher
Teacher limited
A 'Teacher limited' can still:
Teach classes
Set their availability
See a report of their previous classes via Class Admin
Change their student profile
Only teach the classes assigned to them, without the ability to initiate new schedules
The main reason to use a Teacher limited, role rather than a Teacher role, is if you wanted to limit the user's ability to create classes. Teachers in "teacher limited" mode face additional restrictions, including being unable to schedule their own classes and requiring administrators to create bookings for them.
That means there is no button for a teacher to add a class. Furthermore, only administrators hold the authority to create class bookings, reinforcing the scheduling restrictions for teachers in this mode.

