I need help with this method in C

append_to_li st: a. b. Ask the user to enter the student last name, first name, and email (in the exact order). Check whether a request has already existed by student last name, first name, and email. If a request has the same student last name, first name, and email as an existing request in the list, the function should print a message about request already existed and exit. If the request does not exist, ask the user to enter student age. For any new request, the status is \"pending\". Allocate memory for the structure, store the data, and append it to (add to the end of) the linked list. If the list is empty, the function should return the pointer to the newly created linked list. Othenlvise, add the request to the end of the linked list and return the pointer to the linked list