SDK: How to display the top-level menu in Keyboard Shortcuts？

Hello everyone,
I'm using the following code:

ASErr AIalignPlugin::AddMenus(SPInterfaceMessage* message)
{
	ASErr error = kNoErr;

	SDKAboutPluginsHelper aboutPluginsHelper;
	aboutPluginsHelper.AddAboutPluginsMenuItem(message,
		kSDKDefAboutSDKCompanyPluginsGroupName,
		ai::UnicodeString(kSDKDefAboutSDKCompanyPluginsGroupNameString),
		"AIalign...",
		&this->fAboutPluginMenu);

	AIMenuItemHandle dummyItem;

	AIPlatformAddMenuItemDataUS menuData;
	menuData.groupName = kOtherPalettesMenuGroup; 
	menuData.itemText = ai::UnicodeString("AIalign"); 
	error = sAIMenu->AddMenuItem(message->d.self,
		nullptr,
		&menuData,
		kMenuItemWantsUpdateOption,
		&this->fShowAiAlignMasterDialog); 
	if (error) goto error; 

error: 
	return error;
}

I successfully added the AIalign menu item as a top-level menu item under the window menu, but this menu cannot be found in the Keyboard Shortcuts. If set as a submenu, it can be found. So, I kindly ask for everyone's help and guidance on this matter. Thank you all.