U3425WE, hotkey issue in macOS

I just purchase a Dell U3425WE monitor. I am using it with my MacBook Pro, and a Logitech bluetooth keyboard (Mac version). I downloaded the DDPM (Dell Display and Peripheral Manager) for macOS. I would like to be able to adjust the monitor screen brightness using the keyboard brightness buttons (they sit over the F1 and F2 keys). When I open DDPM, under the "Brightness / Contrast" tab I am able to click the "hotkey" button at the bottom of the screen, and each of the four hotkey options is defaulted to "None". When I select any of the fields, DDPM does not recognize any of my keystrokes, on either the bluetooth keyboard or my MacBook Pro keyboard. Any suggestions on how I can change the hotkey settings?