Making a "win round" function

[Subphoria]

Sorry for a kinda open end question,
I want to make a win round function to be triggered by lua_run from source_SDK.

Like, map > player goes into win area > triggers lua_run > winroundfunction

I know how to do all of that apart from i cant understand how to make the winning round function inside the LUA.

This is what i have so far which might be totally wrong:

if SERVER then
util.AddNetworkString("WinsRoundHook")
hook.Add("???","Inform Winner of Round", function(winner ?)
    net.Start("WinsRoundHook?")
        net.WriteString(winner:GetName())
		
    net.Send(?????)
    victim:PrintMessage(HUD_PRINTCENTER,ply()??:GetName ().." has won the round\n")

end)
 end
 
--Clientside
if CLIENT then 
local showWinRound = false
local winner = nil

net.Receive("WinsRoundHook", function(len)
    winner = net.ReadString()
    showWinRound = true
    timer.Simple(14, function()
        showWinRound = false
        winner = nil
    end)
end)

surface.CreateFont("winfont",
{
font = "coolvetica",
size = 24,
weight = 40000,
antialias = true,
shadow = false
})	
 
hook.Add("HUDPaint", "DisplayWinRoundStuff", function()
    if winner and showWinRound then

   draw.RoundedBox( 10, 2, ScrH() / 2, 375, 80, Color( 0, 0, 0, 150 ) )
   draw.SimpleText("Won Round", "winfont", 5, ScrH() / 2 + 16, Color(255,255,255,255))
   draw.SimpleText(winner, "winfont", 5, ScrH() / 2 + 42, Color(180,20,20,255))

 end
end)

end