You can track specific actions visitors take on your site in Facebook by installing Facebook event codes on your pages.
Facebook event codes will not work if you installed the Facebook pixel with the HubSpot Ads tool. If you want to add Facebook event codes to your pages, you must install the Facebook pixel code manually by adding it to the footer HTML of your website pages. If you install the Facebook pixel code manually, you will not be able to create Facebook website audiences from HubSpot.
in most instances, Facebook event codes will conflict with other codes on your page when added to the Head HTML. In order to ensure the Facebook even code fires correctly, add it to the Footer HTML.
In the dashboard, hover over the page and click Edit.
Click to expand Advanced Options.
In the Footer HTML section, paste the Facebook event code.
In the upper right, click Publish or Update.
Necessary disclosure: HubSpot will automatically place Facebook event codes on your website pages where the HubSpot tracking code is present. These event codes send and track information about your website visitors back to Facebook, which enables conversion tracking.