Once your site is successfully connected, you should have another tab that opens the site URL you entered with a box indicating that it is connected to the debugger (don’t worry; that box is only visible to you, not to anyone who might be visiting your site.)
In the left side panel of the Tag Assistant tab, you’ll see a summary describing all the events that occur on the page you’re monitoring. At a minimum, you should see at least three events listed here: Container Loaded, DOM Ready, and Window Loaded. If you see more than three events listed, that’s okay. But if any of these three major events are missing, you will need to check why those events are missing because it is a sign that something needs to be corrected.
When you click on any of the events in the timeline, you will see all the tags set to fire when that event occurs. Click on any of the tags to see more detailed information about its triggers, properties, and whether there are any blocking triggers associated with it.
While working in Preview and Debug mode, you are the only one who can see information about your tags. That said, let’s say you find a problem that you need to bring to someone else’s attention. You can share your preview with that person via Tag Assistant. In the Tag Assistant tab, look for the three vertical dots in the top right, click on them and choose Share. From there you can select the tags to debug to get a shareable link to send to the person who can help you.
Once all the tags are activated successfully, go ahead and publish them. From the GTM dashboard, press the button Send in the top right corner and you will be asked to review your changes. If everything looks good, enter a name and description for the new container version and publish it.
When you publish changes to GTM, a new version of your container is created. If a problem occurs and you need to revert to a previous version of the container, all you have to do is click the icon Versions button at the top of the GTM dashboard, choose the version you want to revert to, click ActionThen To publish.
Let’s say you’re migrating tags from another tag manager or tags encoded directly on your site. In that case, Google recommends setting up all your tags in GTM, then removing the old tags all at once, and publishing the GTM container with the new tags as quickly as possible. You may have a very small gap in data collection, but there should be no more problems once the new tags go live.