How can I change theme variant to dark in phpBB 3.2.2 Ravaio Theme

My nephew bought Ravaio theme. But we couldnt change the dark present in phpBB board.

Theme variant empty. Only white page active. How can I enable dark?

I upload /ext extentions and /styles theme . I clear cookies but nothing change. We have got last update from Ravaio.

And my extentions empty in 3.2.2

Any help?