Setting up Bing Universal Event Tracking (UET) tag for CS-Cart
У вашего броузера проблема в совместимости с HTML5
Google Tag Manager is a tag management system with which you can easily update tags and code snippets on a website or in a mobile application. By placing the tag container, you can perform all the work with the tags right in the Manager interface. This saves time, reduces errors and eliminates the need to seek help from the developer.
Link on Add-on: https://www.simtechdev.com/addons/marketing/google-tag-manager.html