Unknown or incomplete command when trying to use any Bssentials command

[ToatyBread]

Hello, I'm trying to use the Bssentials mod for fabric so I can use /nick but when I type out the command and hit enter nothing happens. All that appears is
"Unknown or incomplete command, see below for error
/nick<--[HERE]"
can ANYONE help me with this?

Edit: Replying with "same" is not a good answer.

[ghost]

this is a problem with perrmisions in op you can use commands.. i have the same problem with permissions setting bssentials.comand.nick doesn't work