language.routing.yml

language_negotiation_url:
  pattern: '/admin/config/regional/language/detection/url'
  defaults:
    _form: 'Drupal\language\Form\NegotiationUrlForm'
  requirements:
    _permission: 'administer languages'

language_negotiation_session:
  pattern: '/admin/config/regional/language/detection/session'
  defaults:
    _form: 'Drupal\language\Form\NegotiationSessionForm'
  requirements:
    _permission: 'administer languages'

language_negotiation_selected:
  pattern: '/admin/config/regional/language/detection/selected'
  defaults:
    _form: 'Drupal\language\Form\NegotiationSelectedForm'
  requirements:
    _permission: 'administer languages'