util/resolveProductionUrl.ts
import { APIRoute } from 'cms/APIRoute'
const previewSecret = process.env.NEXT_PREVIEW_SECRET // Copy the string you used for SANITY_PREVIEW_SECRET
const projectUrl = process.env.NEXT_PUBLIC_PROJECT_URL
/**
* Create Page preview API route for a slug using:
* - `NEXT_PREVIEW_SECRET`
* - `NEXT_PUBLIC_PROJECT_URL`
*
* @param {APIRoute} page Page route to resolve
* @returns {string} The preview url
*/
export default function resolvePreviewUrl(page: APIRoute): string {
// eslint-disable-next-line @typescript-eslint/restrict-template-expressions
return `${projectUrl}/api/preview?secret=${previewSecret}&slug=${page.slug.current}`
}