An easy to install module for your Prestashop for easy GTM integration
Tested on Prestashop 1.6.1.23. If you successfully installed it on other versions - please let me know or create a PR / Issue.
You should create a zip archive from the folder msiliunas_googletagmanager and upload it to your prestashop installation.
All you need to do is enter your Google Tag Manager ID in the module configuration screen.
Have fun!