Strapi custom graphql mutation return null

Hi,
I’m customizing order-details in the backend as this →

        module.exports = {
  resolver: {
    Mutation: {
      createOrderDetail: {
        description: "create an order detail",
        resolverOf: "application::order-details.order-details.create",
        resolver: async (obj, options, { context }) => {
          const data = context.request.body;

          try {
            const result = await strapi.api["order-details"].services[
              "order-details"
            ].create(data);
            return sanitizeEntity(result, {
              model: strapi.models["order-details"],
            }); 

but It won’t return expected data

– the mutation –

createOrderDetail(

      input: {

        data: {

          orderQuantity: $orderQuantity

          price: $price

          salePrice: $salePrice

          total: $total

          published_at: $published_at

          product: $product

          productDiscount: $productDiscount

        }

      }

    ) {

      orderDetail {

        id

        total

      } 

– returned result –

what is the correct way to handle the custom graphql mutation?

documentation

and

forum

this won’t help, I tried both ways!

thank you.