How to set resolution of HDMI out of XPS 15?

Hi,

I would like to know if there is anyway I can customize the resolution of HDMI out of XPS 15 9560. I want to record my powerpoint presentation using HDMI out going to Blackmagic Video Assist 4KRecorder. The recorder reads the HDMI signal from XPS is 4k resolution. I only need 1080p resolution to record my Powerpoint into video. There is no setting in the recorder to change the resolution to be recorded.  Is there a way to set the HDMI out to1080p resolution?

thank you,