Robert DeVore

This plugin will automatically update the rel tags for links with specific domains in the classic editor content, and the new core block editor.
The Link Attributes for Publishers plugin is designed to assist content authors in complying with Google’s suggestions regarding proper tagging of sponsored and user-generated content (UGC) links. This plugin simplifies the process of adding rel tags for sponsored, ugc, and nofollow links to ensure your website meets Google’s specifications for link attribution.
<h3>Who is this for?</h3>
This plugin is particularly useful for:
<ul>
<li>Content Authors: Easily add <code>rel</code> tags to links without the need for manual coding.</li>
<li>Publishers: Ensure all sponsored and user-generated content links are properly tagged for compliance.</li>
</ul>
Let’s say you want to mark all amzn.to links as <code>sponsored</code> because they’re all affiliate links. This plugin helps you do that automatically to all content, old and new.
<h3>Features</h3>
<ul>
<li>Automatically sets <code>rel</code> tags for sponsored, ugc, and nofollow links.</li>
<li>Allows users to specify domain names for automatic <code>rel</code> tag addition.</li>
<li>Simplifies compliance with Google’s specifications about link attributes.</li>
</ul>

Link Attributes for Publishers

Automatically add sponsored, ugc and nofollow rel tags to specific URL's in your content

david.kane

The <a href="https://www.supadu.com/" rel="nofollow ugc">Supafolio WordPress plugin</a> allows trade publishers to access powerful features through WordPress previously only available to Supacms users which can be easily embedded in your pages using shortcodes.
Features include:
<ul>
<li>Metadata. Display the metadata (e.g. ONIX) for any book in your catalog, including cover image, title, subtitle, author, price, format and link by typing in the ISBN13.</li>
<li>Layouts. Choose how to display your books through a variety of layouts including grid, carousel and list.</li>
<li>Control. Change the metadata that is displayed on the page by overwriting the underlying data through the SupaFolio dashboard.</li>
</ul>

Supafolio

Quickly and easily connect your book metadata (ONIX) to your WordPress site.

Link Attributes for Publishers vs Supafolio