Nextjs 14

You can use Google Tag Manager from nextjs third party libraries.

import { GoogleTagManager } from '@next/third-parties/google'
 
export default function MyApp({ Component, pageProps }) {
  return (
    <>
      <Component {...pageProps} />
      <GoogleTagManager gtmId="GTM-XYZ" />
    </>
  )
}

Nextjs 14

You can use Google Tag Manager and Google Analytics from nextjs third party libraries.

Google Tag Manager

import { GoogleTagManager } from '@next/third-parties/google'
 
export default function MyApp({ Component, pageProps }) {
  return (
    <>
      <Component {...pageProps} />
      <GoogleTagManager gtmId="GTM-XYZ" />
    </>
  )
}

Google Analytics

import { GoogleAnalytics } from '@next/third-parties/google'

export default function MyApp({ Component, pageProps }) {
  return (
    <>
      <Component {...pageProps} />
      <GoogleAnalytics gaId="G-XYZ" />
    </>
  )
}