No support for Drupal version below 9.2.0.

hierarchy_manager.info.yml

@@ -3,7 +3,6 @@ description: Provides API and plugins to build hierarchy views for entites such
 package: Administration
 
 type: module
-core: 8.x
-core_version_requirement: ^8 || ^9 || ^10
+core_version_requirement: ^9.2.0 || ^10
 
 configure: hierarchy_manager.hm_config_form