tocbot block not showing

Seems to work for me with the Bootstrap Barrio Theme

You do need to add the block manually into your theme.
/admin/structure/block

For simplicity, this should maybe be added to the readme

The block is visible and working for both drupal 9.5.5 (php 8.1 and ckeditor 5) as well as Drupal 10.2.3.
No Change required this can be closed.