I try to create a WordPress carousel of posts. How could i add some specific posts to the carousel?
You could create a special category, assign these posts to it, then in the plugin, step 1, Add WordPress Posts dialog, select this category.
Or you could add a tag for these posts, then in the plugin, step 1, Add WordPress Posts dialog, enter the tag to the "Select posts by tags" input box.
You could view this tutorial for how to create a WordPress carousel by selecting categories and tags: https://www.wonderplugin.com/wordpress-carousel-plugin/wordpress-posts-carousel-by-tags//