Extending a Level Editor Tool Bar Menu

Created a plugin that adds a ComboButton to generate a menu on the Level Editors Tool Bar. Now I’m looking to extend this menu, but the it seems I can’t access the extension point.

    if (IsRunningGame())

    FLevelEditorModule& LevelEditorModule = FModuleManager::LoadModuleChecked<FLevelEditorModule>("LevelEditor");

    struct Local
        static void AddMenuCommands(FMenuBuilder& MenuBuilder)
            MenuBuilder.AddSubMenu(FText::FromString("Menu Items"),
                FText::FromString("Menu Item Tool Tip"),

    TSharedRef<FExtender> MenuExtender(new FExtender());
    MenuExtender->AddMenuExtension("MyPluginExtensionPoint", EExtensionHook::After, NULL, FMenuExtensionDelegate::CreateStatic(&Local::AddMenuCommands));

It seems I can’t manage to extend the menu of any other Tool Bar Menu either, like attempting to hook into ProjectSettingsSection

I assume the GetMenuExtensibilityManager I’m looking for is not the one from the LevelEditor but from whichever module it is that Extended the Tool Bar in the first place?