fences-8.x-2.0-rc1/fences.routing.yml

fences.overview:
  path: '/admin/config/user-interface/fences'
  defaults:
    _controller: '\Drupal\system\Controller\SystemController::systemAdminMenuBlockPage'
    _title: 'Fences'
  requirements:
    _permission: 'access administration pages'

fences.settings:
  path: '/admin/config/user-interface/fences/settings'
  defaults:
    _form: '\Drupal\fences\Form\FencesConfigForm'
    _title: 'Settings'
  requirements:
    _permission: 'administer fences settings'