Error: Call to undefined function ... when creating submission from bootstraped Drupal with external PHP script

I'm trying to create webform submission from external PHP script using bootstraped Drupal.

For bootstraped Drupal I'm using this code

define('DRUPAL_DIR', '/var/www/drupal/web');
set_include_path(get_include_path() . PATH_SEPARATOR . DRUPAL_DIR);
chdir(DRUPAL_DIR);

use Drupal\Core\DrupalKernel;
use Symfony\Component\HttpFoundation\Request;

$autoloader = require_once 'autoload.php';

$request = Request::createFromGlobals();
$kernel = DrupalKernel::createFromRequest($request, $autoloader, 'prod')->boot();
$requestStack = Drupal::service('request_stack')->push($request);

from https://www.drupal.org/project/drupal/issues/3243387 🐛 Argument 1 passed to Drupal\Core\Routing\RequestContext::fromRequest() must be an instance of Symfony\Component\HttpFoundation\Request, null given Closed: cannot reproduce

Then I'm trying to create submission as documented here https://www.drupal.org/docs/contributed-modules/webform/webform-cookbook... →

But I'm getting errors

Error: Call to undefined function Drupal\webform\Entity\base_path() in /var/www/drupal/web/modules/contrib/webform/src/Entity/WebformSubmission.php on line 855 #0 /var/www/drupal/web/core/lib/Drupal/Core/Entity/ContentEntityStorageBase.php(87): Drupal\webform\Entity\WebformSubmission::preCreate()

This one I fixed with
require_once DRUPAL_DIR . '/core/includes/common.inc';

But I think that correct approach would be to replace
'uri' => preg_replace('#^' . base_path() . '#', '/', $current_request->getRequestUri()),
with
'uri' => preg_replace('#^' . $GLOBALS['base_path'] . '#', '/', $current_request->getRequestUri()),

Error: Undefined constant "Drupal\webform\Entity\DRUPAL_DISABLED" in /var/www/drupal/web/modules/contrib/webform/src/Entity/Webform.php on line 1164 #0 /var/www/drupal/web/modules/contrib/webform/src/Entity/Webform.php(979): Drupal\webform\Entity\Webform::getDefaultSettings()

fixed with
require_once DRUPAL_DIR . '/core/modules/system/system.module';

Maybe this could be solved by loading \Drupal::moduleHandler()->load('system'); in the webform files.

Thanks