Missing Author

Hi,

My website is https://www.femalesolotravel.com

I have the Pinnacle Free theme by Kendance. I also have installed SEO by Yoast and Jetpack.

Webmaster is displaying the following errors under Structured Data > Items with Errors > Error Type > Missing:Author.

When I click on Missing:Author and click on Test Live Data, it shows the following:
– blog posting: all good
– hentry: all good
– profile page: all good
– unspecified type: Warning!

When I click on Warning, the following message is displayed: Node is empty. Double check that this is desired and consider removing.

I have seen forums where apparently the solution would be modifying the single.php code in the part regarding the author, however in Pinnacle, when I open the Single.php file, there is no such part, so I don’t know where to find it, nor if this would actually be the right solution.

For the rest, I am the administrator and I write most of the articles (but not all). I don’t have an Author profile, but just an Administrator profile (I don’t know if this might be the issue).

So far I had the following options enabled/disabled:
– Users > WordPress SEO settings (by Yoast) > Admin > Exclude user from Author-sitemap is: DISABLED
– SEO > XML Sitemaps > “author/user sitemap” is: ENABLED, I have “DISABLED all users with zero posts” , and have excluded only the following user roles: Contributor, Subscriber.
– Appearance > Theme options > Blog Options > “Show author name with posts?” is: ON

I would like to permanently fix this issue so that is not showing up anymore, also for new posts.

Thanks,
Flavia