Step 1: Embed Surface Tag | Page Router

Navigate to the pages/_document.tsx file.
Add the following code in the Start of <head> tag section.

Check out the How to Get Site ID page to get your site ID.

import Document, { Html, Head, Main, NextScript } from "next/document";
import Script from "next/script";

export default class MyDocument extends Document {
  render() {
    return (
      <Html lang="en">
        <Head>
          <Script
            id="surface-tag"
            src="https://cdn.jsdelivr.net/gh/trysurface/scripts@latest/surface_tag.min.js"
            data-site-id="SITE_ID"
            strategy="beforeInteractive"
          />
        </Head>
        <body>
          <Main />
          <NextScript />
        </body>
      </Html>
    );
  }
}

Using a verified custom domain? Add data-custom-domain="forms.example.com" to the Surface Tag. Follow the custom-domain setup guide before publishing the change.