def check_block(method):
    def new_method(*original_args, **original_kwargs):
        request = original_args[1]
        # if blablabla request.user твоя логика проверки   
            return CustomResponse({"message": "pashov ti naher, kozel"}, status=status.HTTP_403_FORBIDDEN)
        return method(*original_args, **original_kwargs)

    return new_method

class MyView(APIView):
   @check_block
   def post(self, request, *args, **kwargs):
        ... твоя вьюха