How can I send the screen from UE4 to a separate monitor

Hi, I am trying to do a small experience with UE 4, and got stuck into this problem.

I am trying to send the scene that I have worked on UE 4 to a separate monitor (or a screen), but cannot find a way to do this.

I thought that it would be just simple as in sending the PGM to a separate monitor when using OBS or other softwares.

Can anyone help me out?

Thanks.