How to apply SortOrder on Search Criteria Repositories Magento 2?

Magento apply sort order for the search criteria interface repository by using Magento\Framework\Api\SortOrderBuilder Class.

You can do sorting by ASC or DESC order by any field type for a given search criteria repository.

$sortOrder = $this->sortOrderBuilder
            ->setField('created_at')  //FIELD_NAME
            ->setDirection(SortOrder::SORT_DESC) // SORT_TYPE

You can check the given code snippet to fetch orders by created date with the search criteria builder order repository.

namespace Rbj\Sales\Model;

use Magento\Framework\Api\SortOrder;
use Magento\Framework\Api\SortOrderBuilder;
use Magento\Framework\Api\SearchCriteriaBuilderFactory;
use Magento\Sales\Api\Data\OrderSearchResultInterface;
use Magento\Sales\Api\OrderRepositoryInterface;

class SortBySalesOrder
    public function __construct(
        private SortOrderBuilder $sortOrderBuilder,
        private OrderRepositoryInterface $orderRepository,
        private SearchCriteriaBuilderFactory $searchCriteriaBuilderFactory
    ) {

    public function getOrdersByCreatedDate(): OrderSearchResultInterface
        $searchCriteriaBuilder = $this->searchCriteriaBuilderFactory->create();
        $searchCriteriaBuilder->addFilter('state', ['new', 'pending_payment'],'in');

        $sortOrder = $this->sortOrderBuilder

        $searchCriteria = $searchCriteriaBuilder->create();

        return $this->orderRepository->getList($searchCriteria);

You can check the above class, We have applied for sort order on the order search criteria repository to fetch all the results by created date.