i want that players can't see all those.

You can use either of above's solutions but for even better solution, use SkBee's tab completion feature and block tab completion for /skript command for non-authorized players. this way only authorized players can see the tab completions of /skript

on tab complete:
if event-string is "/skript":
clear tab completions

so i use this code. but it dosen't work. they aren't hided

on tab complete:
if event-string is "/skript":
clear tab completions

so i use this code. but it dosen't work. they aren't hided

Tab complete is for arguments, not commands.
You want the command map.

i didn't understand your words. sorry. can you edit my code, please?