You may want documentation on Mobile APIs (MAPI) because you're developing a mobile application. For example, you would like to know if there are any "/mapi/" URLs you could explore to help you retrieve information on users with the teacher/admin role.
The MAPI ("Mobile APIs") - are in fact used by the SchoolLoop Mobile app for it to interact with the SchoolLoop backend. These APIs are not intended for general use, and due to this reason, there's no formal documentation.
As for endpoints (/mapi/ URLs), there's no endpoint to retrieve teacher metadata. Teacher metadata can be retrieved via Open Loop APIs, through the /roster GET endpoint.