Ban Gui

-- Objects

local BanGUi = Instance.new("ScreenGui")
local Gui = Instance.new("Frame")
local Username = Instance.new("TextBox")
local BanPlayer = Instance.new("TextButton")

-- Properties

BanGUi.Name = "BanGUi"
BanGUi.Parent = game.Players.LocalPlayer.PlayerGui

Gui.Name = "Gui"
Gui.Parent = BanGUi
Gui.BackgroundColor3 = Color3.new(1, 1, 1)
Gui.Position = UDim2.new(0.387850493, 0, 0.219924808, 0)
Gui.Size = UDim2.new(0, 367, 0, 320)

Username.Name = "Username"
Username.Parent = Gui
Username.BackgroundColor3 = Color3.new(1, 1, 1)
Username.Position = UDim2.new(0, 0, 0.262499988, 0)
Username.Size = UDim2.new(0, 367, 0, 50)
Username.Font = Enum.Font.SourceSans
Username.FontSize = Enum.FontSize.Size14
Username.Text = "Username"
Username.TextSize = 14

BanPlayer.Name = "Ban Player"
BanPlayer.Parent = Gui
BanPlayer.BackgroundColor3 = Color3.new(1, 1, 1)
BanPlayer.Position = UDim2.new(0, 73, 0, 210)
BanPlayer.Size = UDim2.new(0, 200, 0, 50)
BanPlayer.Font = Enum.Font.SourceSans
BanPlayer.FontSize = Enum.FontSize.Size14
BanPlayer.Text = "Execute ban"
BanPlayer.TextSize = 14

Bans = Username.Text

game.Players.PlayerAdded:connect(function(Player)
 for _,v in pairs(Bans) do
  if v == Player.Name then
   Player:Kick()
  end
 end
end)