Google Tag Manager is a tag management system (TMS) that allows you to quickly and easily update code and related code fragments collectively known as tags on your website or mobile app.
Why GTM
Google Tag Manager allows you to add and update your own tags for conversion tracking, site analytics, remarketing, and more. There are endless ways to track activity across your sites and apps, and the intuitive design lets you change tags whenever possible.
How to integrate with GTM
Ensure you have an active GTM account by following the latest guidelines: Set up and install Tag Manager.
Log into your Google Tag Manager account and select the container associated with the site where you'd like to install Marker.io.
Select New Tag
Give your tag a name, and within Tag configuration, select Custom HTML.
Copy your widget code from app.marker.io into the custom HTML.
Under Triggering, select All Pages.
Save, submit and publish your Tag.
You may need to clear your browser cache for the widget to display.