add_child_page-8.x-1.0/add_child_page.routing.yml

add_child_page.configuration_form:
  path: 'admin/config/content/add-child-page'
  defaults:
    _form: '\Drupal\add_child_page\Form\AddChildPageConfigurationForm'
    _title: 'Add Child Page'
  requirements:
    _permission: 'administer content types'
add_child_page.add_child:
  path: 'node/{node}/child'
  defaults:
    _controller: '\Drupal\add_child_page\Controller\AddChildPage::manage'
    _title: 'Add Child Page'
  options:
    _admin_route: TRUE
  requirements:
    _permission: 'access add child page'
    _custom_access: 'Drupal\add_child_page\Controller\AddChildPage::access'