smsplatform-1.0.x-dev/modules/smsplatform_user/smsplatform_user.routing.yml

smsplatform_user.options:
  path: '/admin/config/sms/user'
  defaults:
    _form: '\Drupal\smsplatform_user\Form\AdminSettingsForm'
    _title: 'User SMS settings'
  requirements:
    _permission: 'administer sms platform'