You can find Headline Sharing under the Headline Sharing tab in the admin settings.
Headline Sharing Admin Options
Headline sharing is still experimental and is in the user feedback stage of feature development. It may not work with all themes, so please check your site after enabling Headline Sharing.
Headline Sharing is Off by Default
Headline Sharing is off by default because it can affect your theme's output. It is recommended to enable this option on a staging site and ensure everything is working there before enabling it in production. If you do not have a staging site, please double-check that your site appears unchanged on the frontend.
To enable headline sharing, select the "Enable Headline Sharing" toggle and save the settings.
Saving and Enabling Headling Sharing
You can then hover or focus on any headline with an ID attribute.