Link nofollow

It depends on if your WordPress site is Gutenberg or the “Classic” editor. Before Gutenberg, there were plenty of plugins that you could try:
https://wordpress.org/plugins/search/nofollow/

But if you’re using Gutenberg, and can’t find a compatible plugin, you may have to do it manually:
https://www.wpbeginner.com/beginners-guide/how-to-add-nofollow-links-in-wordpress/

@marcorroma could you share the plugin you found that do it? Thanks!