Can't we create a field in Model Serializer which is not being used in Object Creation?

Question

Models.py

 class Palika(CreatedInfoModel):
        name = models.CharField(
            max_length=50,
            help_text="Unique | Max: 50 characters | Gaun/Nagar Palika",
        )
        district = models.ForeignKey(
            District, on_delete=models.PROTECT, help_text="Link to District"
        )
        is_default = models.BooleanField(default=False, help_text="By default=False")
        active = models.BooleanField(default=True, help_text="by default=True")


  class Ward(CreatedInfoModel):
        name = models.CharField(
            max_length=50,
            # unique=True,
            help_text="",
        )
        palika = models.ForeignKey(
            Palika, on_delete=models.PROTECT, related_name="wards", help_text="link to Gaun/Nagar Palika"
        )
        active = models.BooleanField(default=True, help_text="by default=True")
    
        def __str__(self):
            return f"{self.name}"

serializers.py

 class PalikaCreateSerializer(BaseModelSerializer):
        wards_names = serializers.ListField(child=serializers.CharField())
        class Meta:
            model = Palika
            # Write only fields
            # 1. Common Write Only fields
            common_write_only_fields = get_common_write_only_fields_create()
            # 2. Custom Write Only fields with respect to model
            custom_write_only_fields = [
                "name",
                "district",
                "wards_names",
                "is_default",
                "active",
            ]
            fields = common_write_only_fields + custom_write_only_fields
            # Extra Kwargs
            extra_kwargs = get_common_extra_kwargs_create()
            extra_kwargs.update(
                {
                    "name": {"write_only": True},
                    "district": {"write_only": True},
                    "wards_names": {"write_only": True},
                    "is_default": {"write_only": True},
                    "active": {"write_only": True},
                }
            )
    
        def create(self, validated_data):
            print(validated_data)
            ward_names = validated_data.pop("wards_names")
            print(validated_data)
            validated_data["name"] = validated_data["name"].title()
            palika = super().create(validated_data=validated_data)
            for ward_name in ward_names:
                Ward.objects.create(
                    app_type=palika.app_type,
                    device_type=palika.device_type,
                    created_date_ad=palika.created_date_ad,
                    created_by = palika.created_by,
                    name=ward_name, 
                    palika=palika
                )
            return palika
    
    
        def validate(self, attrs):
            super().validate(attrs)
            model_name = get_model_name_by_self_obj(self)
    
            # Unique (Case Insensitive) validation
            unique_keys_to_be_checked = []
            unique_ci_char_create_validator = UniqueCICharCreateValidator(
                CORE_APP_IMPORT_STRING, model_name, unique_keys_to_be_checked, attrs
            )
    
            unique_ci_char_create_validator(
                CORE_APP_IMPORT_STRING, model_name, unique_keys_to_be_checked, attrs
            )
    
            # Default Check (Only 1 row with default value can exists)
            default_keys_to_be_checked = ["is_default"]
            single_instance_exists_create_validator = SingleInstanceExistsCreateValidator(
                CORE_APP_IMPORT_STRING, model_name, default_keys_to_be_checked, attrs
            )
    
            single_instance_exists_create_validator(
                CORE_APP_IMPORT_STRING, model_name, default_keys_to_be_checked, attrs
            )
    
            return super().validate(attrs)

I am getting error as below: AttributeError: Got AttributeError when attempting to get a value for field wards_names on serializer PalikaCreateSerializer. The serializer field might be named incorrectly and not match any attribute or key on the Palika instance. Original exception text was: 'Palika' object has no attribute 'wards_names'.