Discussion about creating and rendering documents in Sanity Studio using the HTTP API and `S.documentList()`.

export default () =>
  S.list()
    .title('Content')
    .items([
      S.listItem()
        .title('Gestione Categorie')
        .child(async () => {
          const { data: categories } = await getCategories();
          return categories?.map((element) =>
            S.document()
              .title(carTypes[element])
              .documentId(`category-${element.toLowerCase()}`)
              .schemaType('categoriesSettings')
          );
        }),
      // Add a visual divider (optional)d
      S.divider(),
      // List out the rest of the document types, but filter out the config type
      ...S.documentTypeListItems().filter(
        (listItem) => !['categoriesSettings'].includes(listItem.getId())
      ),
    ]);

import S from '@sanity/desk-tool/structure-builder';
import carTypes from './static/categories';
import axios from 'axios';
import { IGetCategoryResponse } from '../server/src/controllers/getCategoriesController';
const http = axios.create({
  baseURL: '<http://localhost:5000/api/v1>',
  timeout: 1000,
});

function getCategories(): Promise<IGetCategoryResponse> {
  return http.get('/cms/categories').then((res) => res.data);
}

export default () =>
  S.list()
    .title('Content')
    .items([
      S.listItem()
        .title('Gestione pagina dei risultati')
        .child(
          S.list()
            .title('Risultati per:')
            .items([
              S.listItem()
                .title('Categoria')
                .child(async () => {
                  const { data: categories } = await getCategories();
                  return categories?.map((element) =>
                    S.document()
                      .schemaType('categoriesSettings')
                      .title(carTypes[element])
                      .documentId(`category-${element}`)
                  );
                }),
            ])
        ),
      // Add a visual divider (optional)d
      S.divider(),
      // List out the rest of the document types, but filter out the config type
      ...S.documentTypeListItems().filter(
        (listItem) => !['categoriesSettings'].includes(listItem.getId())
      ),
    ]);

By putting a string in this method, it will create a document with that ID if it doesn't already exist. 

// deskStructure.js
...
S.listItem()
  .title('Categories')
  .child(
    S.documentList()
      .title('Categories')
      .filter('_type == "categoriesSettings"')
  ),

<dataset-name>

export async function postNewCategories(categories: string[]): Promise<void> {
  try {
    await <http://http.post|http.post>('/data/mutate/production', {
      mutations: categories.map((category: string) => ({
        create: {
          _id: category,
          _type: 'categoriesSettings',
          title: 'category',
        },
      })),
    });
  } catch (err) {
    console.log(err);
    throw new Error(err.message);
  }
}

S.documentList()
      .title('Categories')
      .filter('_type == "categoriesSettings"')

*[_type=="resultBrandsSettings"]

sanity documents query '*[_type == "resultBrandsSettings"]'

export async function postNewBrands(brands: IBrand[]): Promise<void> {
  try {
    await <http://http.post|http.post>('/data/mutate/production', {
      mutations: brands.map((brand: IBrand) => ({
        createIfNotExists: {
          _id: brand.id,
          _type: 'resultBrandsSettings',
          title: brand.name,
        },
      })),
    });
  } catch (err) {
    throw new Error(
      `Sanity API Error: status:${err?.response?.status}, statusCode: ${err?.response?.statusText}`
    );
  }
}

categories [
  'cabrio-coupe',
  'city-car',
  'minivan',
  'other',
  'sedan',
  'suv',
  'van',
  'wagon'
]
Error: Sanity API Error: status:409, statusCode: Conflict