I want to show only posts from specific category

Thanks for your post,

Display form categories/ taxonomy terms only available in premium version.

Please see the screenshot how does it works
https://i.imgur.com/nnT8E2J.png

Here is the pro link you may check out
https://www.pickplugins.com/item/post-grid-crete-awesome-grid-from-any-post-type-for-wordpress/

Regards