Currently, only Facebook and Twitter (X) are supported social media accounts. When entering those, a meta tag gets added with the author information. Both side-wide and author-wide are possible.
Since July 2024, Mastodon has added support for a new meta tag, that will highlight the authors’ profile when posting a link to the post / site.
I’d love to be able to input a Fediverse address (e.g. @ghost@example.org) either into the author profile, or into the side-wide social media accounts setting, and that info being added to the head of the HTML (in this case like this: <meta name="fediverse:creator" content="@ghost@example.org" />).
More information about this: Highlighting journalism on Mastodon - Mastodon Blog
(The post mentions that it’s only rolled out for servers running nightly - that is now outdated information. It’s released now.)
Alternative solutions like adding the author to the secondary navigation (like mentioned in this topic) wouldn’t be possible as it needs to have the tag.