I am not able to view the edges on my cube.

Hi, at 27:22 you go into a wireframe view mode with the triangulate modifier on the cube. I added triangulate modifier in object mode then switched over to wireframe mode and I do not see the edges.

I noticed there are some options in the  modifiers that is different from your version. How do I enable the view so I can see the edges that is applied when the triangulate modifier is on?