gridstack-8.x-2.5/modules/gridstack_ui/gridstack_ui.links.menu.yml

entity.gridstack.collection:
  title: GridStack
  route_name: entity.gridstack.collection
  description: 'Manage GridStack optionset.'
  parent: system.admin_structure

gridstack.settings:
  title: GridStack UI
  route_name: gridstack.settings
  description: 'Manage GridStack UI.'
  parent: entity.gridstack.collection