I have installed the GTM Module and DataLayer Module on Drupal 8. But if I want to inspect the tags fired, there is no GTM Preview and Debug mode option to be enabled on the module. Does this means we have to use the preview and debug mode from the standard GTM ? And if yes then what is the advantage of it being on the standard GTM but not on the module.
GTM Module : https://www.drupal.org/project/google_tag
I'm also using dataLayer Module : https://www.drupal.org/project/datalayer
GTM preview mode relies on 3rd party cookies from the googletagmanager.com domain.
The module runs on your website, and therefore can only set cookies for your domain. It cannot set cookies on the googletagmanager.com domain.
Also for one of the Cookies GTM generate what looks like a unique token (that the cookie is called "gtm_auth" is suggestive of its purpose). Presumably GTM compares the value from the cookie to a value that is stored somewhere at Google, and a Drupal module would not be able to store a proper token.
