Added tag manager plugin

gatsby-config.js

@@ -91,6 +91,34 @@ module.exports = {
         trackingId: process.env.GA_TRACKING_ID,
       },
     },
+    {
+      resolve: "gatsby-plugin-google-tagmanager",
+      options: {
+        id: process.env.GOOGLE_TAGMANAGER_ID,
+
+        // Include GTM in development.
+        //
+        // Defaults to false meaning GTM will only be loaded in production.
+        includeInDevelopment: false,
+
+        // datalayer to be set before GTM is loaded
+        // should be an object or a function that is executed in the browser
+        //
+        // Defaults to null
+        //defaultDataLayer: { platform: "gatsby" },
+
+        // Specify optional GTM environment details.
+        //gtmAuth: "YOUR_GOOGLE_TAGMANAGER_ENVIRONMENT_AUTH_STRING",
+        //gtmPreview: "YOUR_GOOGLE_TAGMANAGER_ENVIRONMENT_PREVIEW_NAME",
+        //dataLayerName: "YOUR_DATA_LAYER_NAME",
+
+        // Name of the event that is triggered
+        // on every Gatsby route change.
+        //
+        // Defaults to gatsby-route-change
+        //routeChangeEventName: "YOUR_ROUTE_CHANGE_EVENT_NAME",
+      },
+    },
     {
       resolve: `gatsby-plugin-hotjar`,
       options: {

package.json

@@ -11,6 +11,7 @@
     "dotenv": "^8.2.0",
     "gatsby": "^2.19.7",
     "gatsby-plugin-google-analytics": "^2.3.13",
+    "gatsby-plugin-google-tagmanager": "^2.9.0",
     "gatsby-plugin-hotjar": "^1.1.1",
     "gatsby-plugin-sass": "^2.3.4",
     "gatsby-theme-apollo": "^3.0.2",