nvram error

I tried to reset nvram(or pram) with the terminal app.

I put sudo nvram -c and the terminal said

Error clearing firmware variable fmm-computer-name: (iokit/common) not permitted

and couldn't reset nvram.

Are there any way to overcome or detour this error message and to reset nvram(pram)?

I'm using 2017 mbp with 2 thunderbolt ports.

Thanks