Having issue in handling multipart form data in django rest framework

I have an addproduct api in which frontend is sending a multipart/formdata in a post axios call. multipart/form-data is used because there is an image field that needs to be sent in arrays.

But I got the following error.

Category field is required

The data is sent like this

name: Soap
category[0]: 7
category[1]: 23
brand: 7
collection: 11
availability: in_stock
warranty: no_warranty
service: cash_on_delivery
rating: 3
best_seller: true
top_rated: true
featured: true
main_product_image: (binary)
merchant: 2
variants[0][product_id]: fgfdg
variants[0][price]: 127
variants[0][quantity]: 1
variants[0][color]: red
variants[0][size]: M
variants[0][variant_availability]: not_available
variants[0][variant_image]: (binary)
variants[1][product_id]: fgfdg
variants[1][price]: 127
variants[1][quantity]: 1
variants[1][color]: red
variants[1][size]: M
variants[1][variant_availability]: not_available
variants[1][variant_image]: (binary)

The same issue is with the variants.

My models:

class Variants(models.Model):
    product_id = models.CharField(max_length=70, default='OAXWRTZ_12C',blank=True)
    price = models.DecimalField(decimal_places=2, max_digits=20,default=500)
    size = models.CharField(max_length=50, choices=SIZE, default='not applicable',blank=True,null=True)
    color = models.CharField(max_length=70, default="not applicable",blank=True,null=True)
    variant_image = models.ImageField(upload_to="products/images", blank=True,null=True)
    thumbnail = ImageSpecField(source='variant_image',
                               processors=[ResizeToFill(100, 50)],
                               format='JPEG',
                               options={'quality': 60})
    quantity = models.IntegerField(default=10,blank=True,null=True)  # available quantity of given product
    variant_availability = models.CharField(max_length=70, choices=AVAILABILITY, default='available')

    class Meta:
        verbose_name_plural = "Variants"

    def __str__(self):
        return self.product_id

#Product Model

class Product(models.Model):
   
    merchant = models.ForeignKey(Seller,on_delete=models.CASCADE,blank=True,null=True)
    category = models.ManyToManyField(Category, blank=False)
    sub_category = models.ForeignKey(Subcategory, on_delete=models.CASCADE,blank=True,null=True)
    brand = models.ForeignKey(Brand, on_delete=models.CASCADE)
    collection = models.ForeignKey(Collection, on_delete=models.CASCADE)
    featured = models.BooleanField(default=False)  # is product featured?
    best_seller = models.BooleanField(default=False)
    top_rated = models.BooleanField(default=False)
    tags = TaggableManager(blank=True)  # tags mechanism
    name = models.CharField(max_length=150,unique=True)
    main_product_image = models.ImageField(upload_to="products/images", null=True, blank=True)
    thumbnail = ImageSpecField(source='main_product_image',
                               processors=[ResizeToFill(100, 50)],
                               format='JPEG',
                               options={'quality': 60})
    slug = models.SlugField(max_length=200,blank=True)       
    description = RichTextField(blank=True)
    #picture = models.ImageField(upload_to="products/images", null=True, blank=True)
    picture = models.ManyToManyField(ImageBucket,null=True,blank=True,verbose_name="Add extra 3 images")
    rating = models.IntegerField(choices=((1, 1),
                                               (2, 2),
                                               (3, 3),
                                               (4, 4),
                                               (5, 5))
                                      )
    availability = models.CharField(max_length=70, choices=AVAILABILITY, default='in_stock')
    warranty = models.CharField(max_length=100, choices=WARRANTY, default='no_warranty')
    services = models.CharField(max_length=100, choices=SERVICES, default='cash_on_delivery')
    variants = models.ManyToManyField(Variants,related_name='products')

My view:

class ProductAddAPIView(CreateAPIView):
    permission_classes = [IsAuthenticated]
    parser_classes = [MultiPartParser,JSONParser,FormParser]
    # queryset = Product.objects.all()
    serializer_class = AddProductSerializer

Here I have used parser class just in case if it works.

Updated Code:

class  AddProductSerializer(serializers.ModelSerializer):
    id = serializers.PrimaryKeyRelatedField(read_only=True)
    variants = VariantSerializer(many=True)
    slug = serializers.SlugField(read_only=True)
    
    class Meta:
        model = Product
        fields = ['id','merchant','featured', 'top_rated','category','brand','collection','sub_category',
                  'name','slug','description', 'main_product_image','best_seller','picture',
                  'rating','availability','warranty','services','variants']
        #depth = 1

    def create(self, validated_data):
         #user = self.context['request'].user

         picture_data = validated_data.get('picture')

         merchant = validated_data.get('merchant')

         category_data = validated_data.get('category')

         featured = validated_data.get('featured')

         top_rated = validated_data.get('top_rated')
         brand = validated_data.get('brand')
         collection = validated_data.get('collection')
         sub_category = validated_data.get('sub_category')
         name = validated_data.get('name')
         description = validated_data.get('description')
         main_product_image = validated_data.get('main_product_image')
         best_seller = validated_data.get('best_seller')
         rating = validated_data.get('rating')
         availability = validated_data.get('availability')
         warranty = validated_data.get('warranty')
         services = validated_data.get('services')

        #variants_logic


         variants_data = validated_data.get('variants')
         #breakpoint()
         print(variants_data)


         # from pudb import set_trace;set_trace()

         #products-logic

         product = Product.objects.create(featured=featured,top_rated=top_rated,
                                          brand=brand,collection=collection,sub_category=sub_category,
                                          name=name,description=description,
                                          main_product_image=main_product_image,
                                          best_seller=best_seller,rating=rating,
                                          availability=availability,warranty=warranty,
                                          services=services,merchant=merchant)
         product.save()


         product.category.set(category_data)             

         # product.variants.set(variants_data)
         product.save()
         for variants_data in variants_data:
             abc = Variants.objects.create(**variants_data)
             product.variants.add(abc)

         product.save()
         return product