If you have analytics/advertising/marketing code snippets you need to implement on your website (like Facebook advertising, Google Advertising, Google Analytics, etc):
First see if you can implement it via the Site settings → Analytics page:
- If not, go to Theme → Files.
- If you're instructed to place the code inside the <head> tags, open _nm-includes.html. If you're instructed to place the code before the closing <body> tag, open _nm-scripts.html. If you don't know, probably go with _nm-scripts.html and test it to make sure it works. If it doesn't work, try _nm-includes.html and test.
Scroll all the way to the bottom of the file where you'll see:
- Paste your code in between those comments or below them (it doesn't matter).