Twig/CmsExtension.php
public function cmsArea(string $areaName, ?Page $page = null) : string
    {
        $blocks = $this->blockRepository->findForAreaAndPage($areaName, $page);
        
        $out = '';

        foreach ($blocks as $block) {
            $out .= sprintf('<!-- block id="block_%s" -->', $block->getId());

            $out .= $this->blockManager->render($block);

            $out .= sprintf('<!-- /block id="block_%s" -->', $block->getId());
        }

        return $out;
    }
public function cmsArea(string $areaName, ?Page $page = null) : string
    {
        $blocks = $this->blockRepository->findForAreaAndPage($areaName, $page);
        
        $out = '';

        foreach ($blocks as $block) {
            $out .= sprintf('<!-- block id="block_%s" -->', $block->getId());

            $out .= $this->blockManager->render($block);

            $out .= sprintf('<!-- /block id="block_%s" -->', $block->getId());
        }

        return $out;
    }
cms_area('area_name', page)
cms_area('area_name') for global page