inPreview example

if (!$block instanceof BlockPluginInterface) {
      return;
    }

    // Set block access dependency even if we are not checking access on     // this level. The block itself may render another     // RefinableDependentAccessInterface object and need to pass on this value.     if ($block instanceof RefinableDependentAccessInterface) {
      $contexts = $event->getContexts();
      if (isset($contexts['layout_builder.entity'])) {
        if ($entity = $contexts['layout_builder.entity']->getContextValue()) {
          if ($event->inPreview()) {
            // If previewing in Layout Builder allow access.             $block->setAccessDependency(new LayoutPreviewAccessAllowed());
          }
          else {
            $block->setAccessDependency($entity);
          }
        }
      }
    }

    // Only check access if the component is not being previewed.