Instructors requests option allows the admin to manage users' requests to become an instructor.
Users can submit a form for becoming an instructor right from their profile page:
The screenshoot takent from the Masterstudy theme
On the Instructors' request page, the site admin can see all the requests and is able either to approve or decline them.
The admin of the website can reject the user's request and describe the reasons for rejection in the message which the user will get as a notification on his profile page.
The option History will show the history of the requests from a particular user.