cool_message-8.x-2.0/cool_message.routing.yml

cool_message.admin_config:
  path: '/admin/config/user-interface/coolmessage'
  defaults:
    _form: '\Drupal\cool_message\Form\CoolMessage'
    _title: 'Coolmessage'
  requirements:
    _permission: 'access administration pages'
  options:
    _admin_route: TRUE