How to Embed Third-Party Scripts in Body Tag
To do so, locate the Miscellaneous HTML box under System > Configuration > Design (under General tab) > Footer. Paste the code directly in the box and save the data.
If your script requires refreshing the cache, do so by navigating to Catalog > Search Indexing. Click the [Refresh Index] button to request cache indexing.
Once completed, the embedded code will be available on your store.