There are few events that you can listen for:
|onOpen||Every time instance is opened (both show and initialize).|
|onClose||Every time instance is closed.|
|onInit||When instance is opened for the first time.|
|onShow||When opening instance after initial open.|
|onSlideChange Pro||Called on slide change.|
Set up callback function at specific property on props object, e.g.
fsLightboxInstances['lightbox'].props.onSlideChange = (fsLightbox) => console.log(fsLightbox);