auctions-1.0.x-dev/modules/auctions_commerce/auctions_commerce.routing.yml

auctions_commerce.mail_settings:
  path: '/admin/config/system/auctions-commerce'
  defaults:
    _form: '\Drupal\auctions_commerce\Form\AuctionsCommerceMail'
    _title: 'Auctions Commerce mail notices'
  requirements:
    _permission: 'administer site configuration'