In order for this option to work you need to assign the F12 Key as a shortcut to the Do Not Disturb feature.
For this go to your System Preferences > Keyboard > Shortcuts. Select from the left list Mission Control and on the right assign the F12 key combination to the Turn Do Not Disturb On/Off option. See the image below.
The first time when CleanSpark will try to toggle the DND feature it will ask you to grant access using the accessibility features.
Open System Preferences > Security & Privacy, select from the left list Accessibility and make sure that on the right CleanSpark is allowed to have control. See the image below.