If you'd like to add multiple authors to a byline on your post or add a different author other than yourself, you'll need to first enable bylines for your publication.
Head to your publication's Settings page and click on Publication Details in the left navigation bar. In this section, click the toggles next to "Show bylines on posts" and "Show images on bylines".
To disable bylines on posts, click on the toggles to the left in this section.
