Add publicize to the “supports” array of your custom post type

Hi,
i have been reading an article on getting custom post type to work with jetpack publicize

it says this:

Simply add publicize to the “supports” array of your custom post type, in the functions.php file, found in your theme folder (provided you’ve created your custom post type there).

Like this:
‘supports’ => array ( ‘title’, ‘editor’, ‘excerpt’, ‘publicize’, ‘thumbnail’, ‘comments’, ‘revisions’, ‘custom-fields’, ‘page-attributes’, ),

what exactly do i need to add to allow your plugin custom ‘listings’ to work in publicize, so that when a new add is posted it gets shared on social media?