If you're looking to add some sort of Google tag, Google Analytics, or other tracking code to your funnel or website, this is how to do this.
Go to Site and click on Funnels.
Select the specific funnel you want to add the code to.
Go to Settings and paste the tracking code in the provided field.
Repeat the process for each funnel where you need the code.
To add the code to your website, navigate to Sites, select Websites, go to Settings, and paste the tracking code in the Head tracking code section.
This works for Google Analytics, Facebook Pixel, Google Tag Manager, etc.