Here’s how to update the icon emoji value of a Notion page using the Notion API.

I’ll assume you have the Notion client initialized:

import { Client } from '@notionhq/client'

//...

const notion = new Client({ auth: process.env.NOTION_API_KEY })

Let’s say the page id is stored in the page_id variable.

Then you can do this to set the value of the page icon to a new emoji:

await notion.pages.update({
  page_id: page_id,
  icon: {
    type: 'emoji',
    emoji: '✅',
  },
})