Thanks for reaching out.
There is no such option to add the lightbox option to the images, I would suggest you use a few bundled plugin as an alternative solution which has the features you need. Please visit the links below for more details and plugin usage instructions.
When you use .x-image as christian suggest the lightbox opens, but it doesn’t look very well. A navigation bar appears at the top that should lead to the next or previous posts. However, these are like iframes of the whole page.
And by the way, there is no option for using the picture url from the choosen image. It would be nice to have this feature without having to copy the URL manually every time!
Thank you for pointing out. But he might be seraching for an elements which will give him a similar functionaility, and that is why I didn’t referred it. The shortcode is also available for the all available stack, here is the Integirty which is used in the website.