old_contents: from django.shortcuts import render
  
  # Create your views here.
  
new_contents: from rest_framework.viewsets import ModelViewSet
  
  from invoice import models, serializers
  
  
  class ClientARViewSet(ModelViewSet):
      queryset = models.ClientAR.objects.all()
      serializer_class = serializers.ClientARSerializer
  
  
  class CompanyInvoiceARViewSet(ModelViewSet):
      queryset = models.CompanyInvoiceAR.objects.all()
      serializer_class = serializers.CompanyInvoiceAR.objects.all()
  
  
subject: ADD initial invoice_ar/views.py