There’s a thread here where someone mentioned they had to physically open their unit to get rid of the beep. There’s not much details provided, and the user hasn’t been on these forums since 2023, but it’s a start.
You will probably have to open it up and find the buzzer and physically disconnect it somehow. There doesn’t seem to be a specific software setting to switch it off, but it wouldn’t hurt to ask in that thread in case you get lucky.