Sorry so the plugin doesn’t meet your expectations. Usually it is enough to install, enable plugin and then enable checkboxes in plugin settings to specify what you want to into the lightbox. For example if want to open YouTube videos on your site into the lightbox the enable “Convert YouTube links” checkbox and that’s it. Sometimes it can be a conflicts with 3rd party plugins, but our support are always ready to help. We will happy to help you setup the plugin if you contact us.
BTW, absolutely free version is available in WordPress plugins repository.