The post author sidebar is an optional sidebar that can be set at the individual post level. See post metafield description here https://bovadahub.com/docs/pages-posts-and-archives/posts/
To set the author fields, go into the Users in the WordPress Admin and click ‘Edit’ on the author.
Image: This will be pulled from the main user’s image. If you wish to use an alternative image, you can use the metafield at the bottom of the editor titled ‘User alternative image’
Heading: This will pull in the users name
Subheading: This will pull in from the metafield at the bottom of the editor titled ‘Subheading’
Socials: These fields will be populated by the social settings.
Description: This will be populated by the ‘Biographical Info’ for the user.
CTA Button: This will be set by the ‘User Call To Action Button’ field/
