import Document , { Html , Head , Main , NextScript } from "next/document" ; import { GA_TRACKING_ID } from "../utils/gtag" ; export default class MyDocument extends Document { render ( ) { return ( < Html > < Head > { } < script async src = { `https://www.googletagmanager.com/gtag/js?id=${ GA_TRACKING_ID }` } /> < script dangerouslySetInnerHTML = { { __html : `
              window.dataLayer = window.dataLayer || [];
              function gtag(){dataLayer.push(arguments);}
              gtag('js', new Date());
              gtag('config', '${ GA_TRACKING_ID }', {
                page_path: window.location.pathname,
              });
          ` , } } /> < /Head> < body > < Main /> < NextScript / > < /body> < /Html>); } }