Install Foresite on WordPress

The simplest way is a code-snippet plugin such as WPCode:

1. Install and activate the plugin.
2. Go to Code Snippets → Header & Footer.
3. Paste your Foresite line into Header and save.

If you maintain your own theme, you can instead add the line to header.php just before </head>, or enqueue it in functions.php. Use a child theme so updates don't remove it.

On WordPress.com, adding scripts requires a plan that allows plugins.