Are you looking to against exploiters, or are you trying to find an Admin Command script for your server?

: Secure your script by using a table of allowed UserIds . Before any kick or ban command is executed on the server, the script must verify that the player sending the command is actually authorized.

For a client to change something for everyone, it must send a request to the server via a "RemoteEvent" or "RemoteFunction."

: These require more complexity because the server needs to "remember" the banned user. Server Bans

Most "kick scripts" do nothing except print "Kicked player" in your console. You waste hours of time for zero results.