Can I show it only on selected categories?

Hi and thanks for your kind words.

Sorry I have to disappoint you, but there currently is no such option.

Slobodfan and aliendna51, perhaps there is no option in the plugin dashboard, but you could alter it on the php template or the plugin itself?

Here’s a thread that might help.

https://wordpress.stackexchange.com/questions/103069/display-author-box-on-just-certain-category-posts