How to make a script that Player with Roblox username will spawn as custom character when joined?

How to make a script that when a player named for example "Jeff123" will join my place he/she will spawn as R6 custom character that have humanoid in?

I've put this script in ServerScriptService:

local Replicated = game:GetService("ReplicatedStorage")

game.Players.PlayerAdded:Connect(function(plr)
   local char = plr.Character or plr.CharacterAdded:Wait()

   if plr.Name == "Jeff123" then
      local Char1 = Replicated.Character1:Clone()
      Char1.Parent = game.StarterPlayer
      Char1.Name = "StarterCharacter"
      local Humanoid = Instance.new("Humanoid")
      Humanoid.Name = "StarterHumanoid"
      Humanoid.Parent = game.StarterPlayer
      char:LoadCharacter()
   end
end)

And then i put the custom character named "Character1" in ReplicatedStorage

But when i renamed "Jeff123" to my Roblox username to test if it works, it didn't work and there were no errors in Developer Console :(