Unable to create @Body converter for class

i'm trying to call post api using retrofit when i call it i got

Unable to create @Body converter for class CreateOrderRequest (parameter #1) for method CheckOutService.createOrder

    @WorkerThread
     suspend fun createOrderService(body: CreateOrderRequest) {
        if (networkAvailable()) {
            val retrofit = Retrofit
                .Builder()
                .baseUrl(BASE_URL)
                .addConverterFactory(MoshiConverterFactory.create())
                .build()

            val service = retrofit.create(CheckOutService::class.java)
            service.createOrder(body)
        }
    }

Models

data class CreateOrderRequest(
    val cardItem: ArrayList<JSONObject>,
    val deliveryCost: String,
    val deliveryTime: String,
    val lat: String,
    val long: String,
    val name: String,
    val note: String,
    val paymentMethod: String,
    val phone: String,
    val status: String,
    val subTotal: String,
    val timeStamp: JSONObject,
    val total: String
)

data class CardItem(
    val categoryID: String,
    val detailes: String,
    val hasDiscount: Boolean,
    val image: String,
    val inStock: Boolean,
    val name: String,
    val oldPrice: String,
    val price: String,
    val productID: String,
    val qty: String,
    val variant: String,
    val subCategoryID: String,
    val subSubCategoryID: String
)

here is the service

interface CheckOutService {
    @POST("createOrder")
    suspend fun createOrder(@Body user: CreateOrderRequest)
}