Your question is REST APIs for Course Structure. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
API design: design REST APIs for a three-level Course -> Module -> Lesson structure, covering parameters, request body, response format, authentication / user identity and error responses.
Asked in the API design stage. Visible fragment lists parameters, request body, response format, authentication, and error response as the aspects covered.