Co-authors do not appear in Swiftype search results

I am having difficulties getting co-author plus to work with the search engine Swiftype.

Is there a way to index co-authors so they are entered into search engines like Swiftype? I guess the search engines need to index coauthors() instead of the_author().

Thanks for any advice.

https://www.ads-software.com/plugins/co-authors-plus/