Error when generating link to production environment for preview in Studio v3

productionUrl: async (prev, context) => {
      // context includes the client and other details
      const {client, dataset, document} = context

      if (document._type.includes('page')) {
        const slug = await client.fetch(
          `*[_id == $postId][0].slug.current`,
          {postId: document._id}
        )

        console.log(document._id)
        const params = new URLSearchParams()
        params.set('preview', 'true')
        params.set('dataset', dataset)

        return `<https://my-domain.com/${slug}?${params}>`
      }

      return prev
    },

const {getClient, dataset, document} = context

const client = getClient({ apiVersion: '2023-06-27' })