How can I make basic cube visible inside?

So it is a tricky question. I know that I can make BSP Box visible inside using option “hollow”. But a basic cube doesnt have that option. The thing I need to see inner walls of a basic cube.But I cant use BSP Box because a basic cube can be a blueprint, but a BSP box can’t.

Did you activete “Two sided material”. Perhaps you can also invert the UVs

I looked over the details of a basic cube it doesn’t have option “Two sided material” or something like “UV”

Update I have found “Two sided material” in a material details. Now cube is visible inside. Thank you!