Add the Google Analytics Settings Variable in Google Tag Manager
1. Navigate to Admin > Property Settings in Google Analytics and copy your Tracking Id.
The Tracking Id starts with “UA” and is followed by a number. For example: UA-123456-7
2. Sign in into Google Tag Manager, click the Variables option in the left menu, click New and select Google Analytics Settings under Utilities.
3. Name your variable something memorable like, “Google Analytics Settings - My website”, paste your Tracking Id in the text box under Variable Configuration, and click Save.
Setting Cookie Domain to auto is recommended for new implementations to automatically determine the best cookie domain to use. Under More Settings you can customize the variable to behave according to different needs: Fields to set: change the default values of predefined Google Analytics parameters. Custom Dimension: set custom dimensions to be sent with the tags. Custom Metrics: set custom metrics to be sent with the tags. Content Groups: add content groups to the visited pages. Advertising: enable advertising features to include demographic and interest reports. Ecommerce: enable enhanced ecommerce features. Cross Domain Tracking: set cross-domain tracking for several domains measured on the same Google Analytics property.