ezcontent-8.x-dev/modules/ezcontent_node/modules/ezcontent_landing_page/ezcontent_landing_page.module

<?php

/**
 * @file
 * Contains ezcontent_landing_page hook implementations.
 */

use Drupal\Core\Entity\EntityInterface;
use Drupal\Core\Entity\Display\EntityViewDisplayInterface;
use Drupal\node\NodeInterface;

/**
 * Implements hook_entity_view_alter().
 */
function ezcontent_landing_page_entity_view_alter(array &$build, EntityInterface $entity, EntityViewDisplayInterface $display) {
  // Check if entity is a non-new node in either full or AMP view mode.
  /** @var \Drupal\node\NodeInterface $entity */
  if ($entity instanceof NodeInterface && $entity->bundle() === 'landing_page' && !$entity->isNew() && $build['#view_mode'] == 'amp') {
    // Get a list of available view modes for the current entity.
    $view_modes = \Drupal::service('entity_display.repository')
      ->getViewModeOptionsByBundle('node', 'landing_page');
    // Double-check that the AMP view mode is enabled for this node type.
    if (isset($view_modes['amp'])) {
      foreach ($build['#node']->layout_builder__layout->getValue() as $key => $value) {
        foreach ($value['section']->getComponents() as $component) {
          $configuration = [];
          $configuration = $component->get('configuration');
          $configuration['view_mode'] = 'amp';
          $component->setConfiguration($configuration);
        }
        $build['_layout_builder'][$key] = $value['section']->toRenderArray();
      }
    }
  }
}