How to display specific blog posts in a widget?
A new feature
to specify post IDs for displaying in a widget was introduced in version 2.20.0 of the Blog Pro module.
The functionality is available as a part of an active product subscription or support subscription. You can find the 'amasty/module-blog-recent-posts-slider’ package for installing in composer suggest.

This setting is available for ‘Amasty Blog Recent Posts’ and ‘Amasty Blog Recent Posts Slider’ widget types.
After the module installation, you will find a new 'Post IDs' field where you can specify which post IDs are supposed to be shown in a widget: