Custom lightbox for "type:gantt.config.types.project"?

I need to create a custom lightbox for “type:gantt.config.types.project”. I created an event handler “onBeforeLightbox” where its content supposed to change accordingly. However default “project” lightbox opens instead. If I modify data string to “type:gantt.config.types.task” for test purpose then customized lighbox is shown.

Is there a way to customize lightbox for “type:gantt.config.types.project”?

I was able to solve this by specifying

gantt.config.lightbox["project_sections"] = [...]

instead of

gantt.config.lightbox.sections = [...]