entity_reference.routing.yml

EntityReferenceController::create in drupal/core/modules/entity_reference/lib/Drupal/entity_reference/EntityReferenceController.php

Instantiates a new instance of this controller.

entity_reference.autocomplete:
  pattern: '/entity_reference/autocomplete/{type}/{field_name}/{entity_type}/{bundle_name}/{entity_id}'
  defaults:
    _controller: '\Drupal\entity_reference\EntityReferenceController::handleAutocomplete'
    entity_id: 'NULL'
  requirements:
    _access: 'TRUE'