Ole
You are correct. That code cannot be used in the Kiwitrees “custom javascript” tool.
But it is for the new Google “Tag manage” tool. Are you sure you need that? Their website says:
Our free tool Google Tag Manager can help you add tags to your site if you have many analytics and tracking tags. Consider using Google Tag Manager if:
- You use multiple analytics and ad performance tracking tools that require site tags.
- Adding tags to your website slows down your ability to run marketing campaigns.
I would not think either of those apply to many kiwitrees sites. Your existing GA code should still work OK. MIne does.
If you do want to use Tag Manager, you will need to study the implementation instructions for that at the Google Analytics page, and manually apply the full code to a custom header.php file (described here: https://kiwitrees.net/faqs/customisation/customising-themes/).