Заменить в коде JRequest для коректной работы на Joomla 4 - Предлагаю работу

$virtuemart_manufacturer = JRequest::getVar('virtuemart_manufacturer_id');
if(empty($virtuemart_manufacturer)){
  echo ShopFunctionsF::renderVmSubLayout('categories',array('categories'=>$this->category->children));
}

use \Joomla\CMS\Factory;

$app = Factory::getApplication();

if(!$id = $app->input->getInt('virtuemart_manufacturer_id'))
{
    echo ShopFunctionsF::renderVmSubLayout('categories',array('categories'=>$this->category->children));
}

if(!$app->input->getInt('virtuemart_manufacturer_id'))

echo ShopFunctionsF::renderVmSubLayout('categories',array('categories'=>$this->category->children));

$virtuemart_manufacturer = JRequest::getVar('virtuemart_manufacturer_id');
if(empty($virtuemart_manufacturer)){
  echo ShopFunctionsF::renderVmSubLayout('categories',array('categories'=>$this->category->children));
}