Install Google Tag

Find your google tag setting in GA4

Go to your Admin Panel and click the Data Streams item on your GA4 property.

Click the data stream that you setup before

Click the View tag instructions section

Click the Install manually tab and you can find the google tag setting scripts

Copy these scripts and paste them into your pages to setup google tag for GA4

<!-- Google tag (gtag.js) -->
<script async src="https://www.googletagmanager.com/gtag/js?id=G-XXXXXXXX"></script>
<script>
  window.dataLayer = window.dataLayer || [];
  function gtag(){dataLayer.push(arguments);}
  gtag('js', new Date());

  gtag('config', 'G-XXXXXXXX');
</script>