If you have created posts in the Multichannel Communication module, you can highlight the posts in the Featured Posts widget if needed.
To add a Featured Posts widget, you first need to follow the steps described in this article.
The options for the Featured Posts widget are always set via the post in the Multichannel Communication module. This means that when you create a post in the Content Studio, you can directly check the "Add to 'Featured Posts'" option.
You can set this both when creating a post and after publishing it.
Activating this option will display the post in the Featured Posts widget.