How to enable full screen mode without black gap in width?

Hello,

I use LaTex beamer template (pdf) to create my presentation and adobe acrobat 2020 to visualize. I have a 4K windows laptop with an aspect ratio of 16:9.  

However, for presenting in full screen mode (ctrl+L), I see both side in width is black gap (figure below). I guess that is because of the aspect ratio mismatch. I tried modify the Initial View options, but could not solve it. 

I want to present the slides in full mode that will be the entire size of the screen, without any black gap in the side. Pls help.