Google Tag Manager Cs-Cart 4.2

Hello I've installed the Google Tag

design/themes/[YOUR THEME]/templates/addons/my_changes/hooks/index/main_content.pre.tpl

Everything is fine except Google Tag Assistant give me the following error

 tag must not be included in a 

I will appreciate any help

Use the hook instead. This will place it at the end of the page in the html area of the document.