fix: routers member include serializer class, not viewset

api/urls.py

 from django.urls import path, include
 from rest_framework import routers
 
-from .views import LibrarianViewSet, MemberSerializer
+from .views import LibrarianViewSet, MemberViewSet
 
 router = routers.DefaultRouter()
 router.register(r"librarians", LibrarianViewSet, basename="librarians")
-router.register(r"members", MemberSerializer, basename="members")
+router.register(r"members", MemberViewSet, basename="members")
 
 urlpatterns = [
     path("", include(router.urls)),