Unable to add additional Shopify model field to schema

export const schema: GadgetModel = {
  type: "gadget/model-schema/v1",
  storageKey: "DataModel-Shopify-FulfillmentOrder",
  fields: {},
  shopify: {
    fields: [
      "assignedLocation",
      "deliveryMethod", // <-- TRYING TO ADD
      "destination", // <-- TRYING TO ADD
      "fulfillAt",
      "fulfillBy",
      "fulfillmentOrderLineItems",
      "internationalDuties",
      "location",
      "order",
      "orderName",
      "orderProcessedAt",
      "requestStatus",
      "shop",
      "shopifyCreatedAt",
      "shopifyUpdatedAt",
      "status",
      "supportedActions",
    ],
  },
};