Google tag manager - Where to add code
There are 2 steps for adding Google Tag Manager code:
Copy the first code and add here in your Preferences:
Paste in this area:
In the Code Editor, open theme.liquid
In the code area, use the Find feature (Command-F on Mac, Control-F in Windows) and search for:
When you find this line:
Add a some blank lines below the body line:
Copy the second portion, the noscript body code:
Paste that code into that blank area below the body line.
Save your changes.