Bootstrap simple carousel: how to display it on front-end?
If you look at https://git.drupalcode.org/project/bootstrap_simple_carousel/blob/8.x-1.x/src/Plugin/Block/CarouselBlock.php


/**
 * Provides a 'Bootstrap simple carousel' Block.
 *
 * @Block(
 *   id = "bootstrap_simple_carousel_block",
 *   admin_label = @Translation("Bootstrap simple carousel block")
 * )
 */



There is a block for it, called, "Bootstrap simple carousel block". You just have to place it in a region over at /admin/structure/block