Why this Change Apperance script works as Local Script only ?

Hello, my question is in title. I'm trying to change players apperance, but it works only in Starter Character Scripts and as a local script ;/ I tried to make it as a normal script and placed it in ServerScriptService, but don't work at all.

Here is script:

local Player = game.Players.LocalPlayer
local playerCharacter = Player.Character

if Player ~= nil then
    local plrStats = game.ReplicatedStorage.PlayerStorage:WaitForChild(Player.Name):WaitForChild("Points")
    local PlayerGui = Player:FindFirstChild("PlayerGui")
    local DuckName = PlayerGui.DuckGui.CurrentDuck
    local playerBP = Player:FindFirstChild("Backpack")
    local Tool = playerBP:FindFirstChild("Duck")
    local levelUpParticle = game.ReplicatedStorage.Particles.LevelUp:Clone()
    local particleFolder = game.ReplicatedStorage.Particles
    if playerCharacter then
        ---Body Transparency----
        playerCharacter.Head.Transparency = 1
        playerCharacter:findFirstChild("Left Arm").Transparency = 1
        playerCharacter:findFirstChild("Left Leg").Transparency = 1
        playerCharacter:findFirstChild("Right Arm").Transparency = 1
        playerCharacter:findFirstChild("Right Leg").Transparency = 1
        playerCharacter.Torso.Transparency = 1
        playerCharacter.Head.face:Remove()
        ---Duck---
        local RootPart = playerCharacter:findFirstChild("HumanoidRootPart")
        local bellyMain = Instance.new("Part", RootPart)
        bellyMain.Name = "Handle"
        local bellyWeld = Instance.new("Weld", bellyMain)
        bellyWeld.Part0 = bellyMain
        bellyWeld.Part1 = RootPart
        local mesh = Instance.new("SpecialMesh", bellyMain)
        mesh.MeshType = "FileMesh"
        mesh.MeshId = "rbxassetid://9419831"
        mesh.TextureId = "rbxassetid://9419827"
        mesh.Scale = Vector3.new(5,5,5)
        mesh.Offset = Vector3.new(0, -0.5, 0)
    end
end