UriLinkFormatter.php

<?php

namespace Drupal\Core\Field\Plugin\Field\FieldFormatter;

use Drupal\Core\Field\Attribute\FieldFormatter;
use Drupal\Core\Field\FormatterBase;
use Drupal\Core\Field\FieldItemListInterface;
use Drupal\Core\StringTranslation\TranslatableMarkup;
use Drupal\Core\Url;

/**
 * Plugin implementation of the 'uri_link' formatter.
 */
class UriLinkFormatter extends FormatterBase {
  
  /**
   * {@inheritdoc}
   */
  public function viewElements(FieldItemListInterface $items, $langcode) {
    $elements = [];
    foreach ($items as $delta => $item) {
      if (!$item->isEmpty()) {
        $elements[$delta] = [
          '#type' => 'link',
          '#url' => Url::fromUri($item->value),
          '#title' => $item->value,
        ];
      }
    }
    return $elements;
  }

}