HubSpot supports a simple way to add code snippets, such as the Navu embed code, to your site. This article from HubSpot explains how to accomplish this. Follow the link and scroll down to the "Add code snippets to all content hosted on a specific domain" section.
The snippet of code to add is shown below.
<meta name="navu:site" content="SiteCode">
<script async src="https://embed.navu.co/boot.js"></script>
Replace the SiteCode with the specific 6 digit alphanumeric code for your site. Where to find my site code?
Alternatively, once you have signed in to the Navu application, navigate to the Domains tab. Find your site, and click on the INSTALL link. Copy the Navu embed code from there.
Once the Navu plugin has been installed, all published Guides will be visible on your site for their targeted segments, and Navu will immediately start collecting visitor data and display it in the Segments, Guides and Visitors tabs.