What is Google Tag Manager?
Google Tag Manager is a free tool that allows users to add and edit marketing tags (snippets of code or tracking pixels) on a website without having to modify the code.
RedTrack is not integrated with Google Tag Manager. So if you want to update a tracking script on your Landing page, we highly recommend you to do it manually. Moreover, RedTrack settings are easy even without GTM.
However, if you still want to use it with RedTrack scripts, you should be aware that GTM may block the script for no reason and your tracking may be broken.