Error encountered while creating new content on the CMS in Sanity v3.

export default function resolveProductionUrl(document) {
  console.log(document._type)

  const siteUrl = '<https://www>.********'

  if (document._type == 'page' || document._type == 'landingpage') {
    const url = `${siteUrl}/api/preview?slug=/${document._id}`
    console.log('Preview URL:', url)
    return url
  }

  if (document._type == 'work') {
    const url = `${siteUrl}/api/preview?slug=/work/${document._id}`
    console.log('Preview URL:', url)
    return url
  }

  if (document._type == 'stories') {
    const url = `${siteUrl}/api/preview?slug=/stories/${document._id}`
    console.log('Preview URL:', url)
    return url
  }
  console.error('Unrecognized document type:', document._type)
}

import { defineConfig, definePlugin } from "sanity";
import { deskTool } from "sanity/desk";
import schemas from "./schemas/schema";
import resolveProductionUrl from './resolveProductionUrl'

const sharedConfig = definePlugin({
  plugins: [deskTool()],
  schema: {
    types: schemas,
  }
});

export default defineConfig([
  {
    name: "Production",
    title: "Production",
    projectId: "******",
    dataset: "production",
    basePath: "/prod",
    plugins: [sharedConfig()],
    document: {
      productionUrl: async (prev, context) => {
        return resolveProductionUrl(context.document);
      },
    },
  },
  {
    name: "staging",
    title: "Staging",
    projectId: "*******",
    dataset: "development",
    basePath: "/staging",
    plugins: [sharedConfig()],
  },
]);