Markup microformat error: please help!

Hy author of this amazing and free plugin! I insert a small testimonial widget on my site but since day one, Google Search Console advise me about tons of microformat error.

The errors are:

Miss: author
Miss: updated

I receive the error in this line for all the testimonial:

<div class=”slide slide3 testimonial_rotator_slide hreview itemreviewed item has-image cf-tr”>

How can i fix this and have zero error? You can find my rotator here:

http://www.tecnicovincente.it/

Thanks so so much

https://wordpress.org/plugins/testimonial-rotator/