Creating individual sorting at runtime with shopware 6

I am trying to create a sorting without using the Database Migration. I tried doing it as described in the documentation but I get the error that the “custom-sorting” couldn’t be found. I tried using the AbstractListingProcessor instead the subscriber but it didn’t work as well.
Here is a snippet of my code:

  class CustomSortingProcessor extends AbstractListingProcessor
 {
      public function getDecorated() : AbstractListingProcessor
      {
          throw new DecorationPatternException(self::class);
      }

public function prepare(Request $request, Criteria $criteria, SalesChannelContext 
    $context): void

    /** @var ProductSortingCollection $availableSortings */
    $availableSorting = $criteria->getExtension('sortings') ?? new 
     ProductSortingCollection();

    $customSortingProcessorEntity = new ProductSortingEntity();
    $customSortingProcessorEntity ->setId(Uuid::randomHex());
    $customSortingProcessorEntity ->setActive(true);
    $customSortingProcessorEntity ->setTranslated(['label' => 'Custom Sorting']);
    $customSortingProcessorEntity ->setKey('custom-sorting-by');
    $customSortingProcessorEntity ->setPriority(5);
    $customSortingProcessorEntity ->setFields([
        [
            'field' => 'deepLearning.sold',
            'order' => 'desc',
            'priority' => 1,
            'naturalSorting' => 0,
        ],
    ]);

    $availableSorting->add($customSortingProcessorEntity);

    $criteria->addExtension('sortings', $availableSorting);
        }
      }