Turn off the startup chime permanently using terminal

 The startup chime is the only reason I want to smash my Macbook Pro sometimes. And Apple didn't provide an easy way to turn this thing off. I could not find the setting below in Apple support although it mentioned that it should be there for MacOS Big Sur 11 or later. However I am using the latest MacOS Catalina 10, but I still cannot find it.

But I found a solution that works for me.

You can try the below command to turn it off.

 sudo nvram StartupMute=%01 

If you want to turn it on.

 sudo nvram StartupMute=%00 

For me, I prefer to keeping it mute forever.