How to Configure App+Web Tag for Website using existing GTM?

Step 1: Find Measurement ID 

In GA Property Settings, click on Data Streams(BETA). Select the correct web data stream, and copy the ‘MEASUREMENT ID’

Step 2.  Add Google Analytics: App+Web Configuration Tag in GTM

Navigate to the existing GTM container. 

Add a new tag and choose tag type ‘Google Analytics: App+Web Configuration’. Enter Measurement ID saved from Step 1. Make sure ‘Send a page view event when this configuration loads’ is selected if you want to have page_view events automatically collected. Add ‘All Pages’ trigger to this configuration tag and save changes.

Step 3.  Add Google Analytics: App+Web Event Tag in GTM

Add a new tag with type ‘Google Analytics: App+Web Event’. In the field ‘Configuration Tag’, select the configuration tag created in Step 2.

Enter event name and add event parameters if needed. Note event and parameter names are case sensitive, can only contain alphanumeric characters and underscores (“_”). Make sure you do not include space in event or parameter names.

Add trigger and save the tag.