group_content_menu-8.x-1.0-rc3/group_content_menu.links.action.yml

group_content_menu.type_add:
  route_name: entity.group_content_menu_type.add_form
  title: Add group menu type
  appears_on:
    - entity.group_content_menu_type.collection

entity.group_content_menu.add_page:
  route_name: entity.group_content_menu.add_page
  title: 'Add new menu'
  appears_on:
    - entity.group_content_menu.collection
entity.group_content_menu.add_menu_link:
  route_name: entity.group_content_menu.add_menu_link
  title: 'Add link'
  class: \Drupal\menu_ui\Plugin\Menu\LocalAction\MenuLinkAdd
  appears_on:
    - entity.group_content_menu.edit_form