entity.menu.add_link_form:
  route_name: entity.menu.add_link_form
  title: 'Add link'
  class: \Drupal\menu_ui\Plugin\Menu\LocalAction\MenuLinkAdd
  appears_on:
    - entity.menu.edit_form

entity.menu.add_form:
  route_name: entity.menu.add_form
  title: 'Add menu'
  appears_on:
    - entity.menu.collection