Here's my attempt:
local whitelist = { "SteamID1", "SteamID2" } // add your steam id's here
function CheckWhiteList( ply )
ply.kick = false
for k, v in pairs( whitelist ) do
if ply:SteamID == v then
local ply.kick = false
return
else
local ply.kick = true
end
end
if ply.kick then
ULib.kick( ply )
end
end
hook.Add( "PlayerInitialSpawn", "WhitelistCheck", CheckWhiteList )
Not tested.