How do I add the HotJar heatmap code to my site?

HotJar is a third-party analytics tool that generates a heat map of visitors' behavior on the site.  Their tracking code should be placed somewhere on the home page.

Gutensite Control Panel --> Content --> Design --> Customize Design

Typically, any of the fields that offer the editor for text can also accept code, e.g. Text Area.  Switch to <code view>, then paste the code.  Sometimes, you'll see another field called "Allow raw HTML".  Make sure that box is checked, otherwise scripts will be ignored.