Asus Republic of Gamers Swift PG42UQ 41.5" 4K HDR 138 Hz Gaming Monitor - Manual (Page 15)

1-6 Chapter 1: Product Introduction
change the hotkey function, go to the MyFavorite > Shortcut >
Shortcut2 menu.
8. Volume Down button : Decrease the volume level.
9. Volume Up button : Increase the volume level.
For battery replacement:
Open the battery cover and install the batteries into the battery compartment.
Then replace the battery cover.
AAA
AAA