Changes new GA4 in Google Analytics

docs/_config.yml

@@ -22,7 +22,7 @@ baseurl: "/open5gs" # the subpath of your site, e.g. /blog
 url: "https://open5gs.org" # the base hostname & protocol for your site, e.g. http://example.com
 author: "Sukchan Lee"
 github_username: open5gs
-google_analytics: UA-139225646-2
+google_analytics: G-12MQZTB3JH
 
 # Build settings
 markdown: kramdown

docs/_includes/google-analytics.html

@@ -1,10 +1,12 @@
-<script>
-  (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
-  (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
-  m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
-  })(window,document,'script','https://www.google-analytics.com/analytics.js','ga');
+{% if jekyll.environment == "production" %}
+    <script async src="https://www.googletagmanager.com/gtag/js?id={{ site.google_analytics }}"></script>
+    <script>
+      window.dataLayer = window.dataLayer || [];
 
-  ga('create', '{{ site.google_analytics }}', 'auto');
-  ga('send', 'pageview');
-
-</script>
+      function gtag() {
+        dataLayer.push(arguments);
+      }
+      gtag('js', new Date());
+      gtag('config', '{{ site.google_analytics }}');
+    </script>
+{% endif %}