Drupal - Snippet to programatically return a block as a response to AJAX request from controller

myController.php

<?php
use Drupal\Core\Render\Renderer;
use Drupal\Core\Ajax\AjaxResponse;
use Drupal\Core\Form\FormBuilder;

  /**
   * Drupal\Core\Block\BlockManager definition.
   *
   * @var \Drupal\Core\Block\BlockManager
   */
  protected $pluginManagerBlock;

  /**
   * Constructor.
   */
  public function __construct(Renderer $renderer, FormBuilder $formBuilder, BlockManager $pluginManagerBlock) {
    $this->renderer = $renderer;
    $this->pluginManagerBlock = $pluginManagerBlock;
  }

  /**
   * {@inheritdoc}
   */
  public static function create(ContainerInterface $container) {
    return new static(
      $container->get('renderer'),
      $container->get('plugin.manager.block'),
    );
  }

$config = [];
$plugin_block = $this->pluginManagerBlock->createInstance('your_block_machine_name', $config);
// Some blocks might implement access check.
//$access_result = $plugin_block->access(\Drupal::currentUser());
// Return empty render array if user doesn't have access.
// $access_result can be boolean or an AccessResult class
// if (is_object($access_result) && $access_result->isForbidden() || is_bool($access_result) && !$access_result) {
//   // You might need to add some cache tags/contexts.
//   return [];
// }
$html = $plugin_block->build();
// Add the cache tags/contexts.
$this->renderer->addCacheableDependency($html, $plugin_block);
$ajax_response = new AjaxResponse();
$target = "HTML class or id name";
$ajax_response->addCommand(new HtmlCommand($target, $html));
return $ajax_response;


?>