layout_builder_ipe-1.0.x-dev/tests/modules/frontend_links_test/frontend_links_test.module

<?php

/**
 * @file
 * Test module.
 */

use Drupal\Core\Entity\EntityInterface;
use Drupal\Core\Link;
use Drupal\Core\Render\Markup;
use Drupal\Core\Url;
use Drupal\layout_builder\SectionStorageInterface;

/**
 * Implements hook_entity_view_alter().
 */
function frontend_links_test_layout_builder_ipe_links_alter(array &$links, SectionStorageInterface $section_storage, EntityInterface $entity) {
  $links['renderable'] = Link::createFromRoute(t('Frontpage'), '<front>');
  $links['render_array'] = [
    '#type' => 'link',
    '#url' => Url::fromRoute('<front>'),
    '#title' => t('Frontpage'),
  ];
  $links['markup'] = Markup::create('<span>Markup</span>');
  $links['string'] = 'Plain text';
}