A notable feature from Masterstudy - Co-instructor - provides an option for teachers to assign one more instructor to the course.
Update your theme and visit STM LMS > Addons. Find there the Multi-i**nstructors addon and activate** it.
After the option is activated, all the teachers that registered on the website can add instructors to their courses.
The option ‘Add Co-instructor’ will be accessible from the course page. You can open any existed course or create one and a new option will be available on the course settings page.
Find the ‘Add Co-instructor’ between the Teacher and Category options on the course settings page.
Please note you can add user as Co-instructor only if that user is registered on the website as Instructor.