def METHOD_NAME(self, request, *args, **kwargs):
    key = self.kwargs["key"]
    try:
        form_klass = registry.find(key)
    except KeyError:
        return Response(None, status=status.HTTP_404_NOT_FOUND)
    serializer = self.get_serializer(data=request.data)
    if not serializer.is_valid():
        return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)
    data = dict(serializer.data, key=key)
    form = form_klass(data)
    if form.is_valid():
        form.save(request.user)
        return Response(None)
    return Response(form.errors, status=status.HTTP_400_BAD_REQUEST)