I got it off Amazon. Not perfect but it works. The top and bottom go about half way into the black border around the screen. The sides are just to the inside of the black border.
Anti Blue Light and Anti Glare Screen Protector for 22 Inch 16:10 Widescreen Desktop Monitor. Filter Out Blue Light and Relieve Eye Strain to Help You https://www.amazon.com/dp/B085XTZHD4/ref=cm_sw_r_cp_apip_5WEUgoY8zV16D