Use lightbox standalone , without gallery. How use API ?

[YKStepanov]

I only use Lightbox without gallery.
I marked all the objects with the data-nanogallery2-lightbox attribute.
Lightbox works great.
But how can I access the API? I don't have a gallery root element , this code don't work
$('#your_nanogallery2').nanogallery2('method', options);