Integrating with Google Tag Manager
What is Google Tag Manager
How to add Google Tag Manager
GTM is a direct integration, so all you'll need to do is find your container ID.
Your container ID can be found here: https://tagmanager.google.com/#/home
The ID will begin with "GTM-".
Once you have this...
Go to the integrations page in Unstack app and click the + button to the right of the Google Tag Manager integration row.