I cant change a value?

I done a script (local script) that calls a remote event to change a player value Heres the script:

script.Parent.MouseButton1Click:Connect(function()
    game.ReplicatedStorage.NewAdd:FireServer(3)
end)

And heres the script in server script service:

game.ReplicatedStorage.NewAdd.OnServerEvent:Connect(function(plr,AddV)
    plr.Add.Value = AddV
end)

EDIT: I Said that when i click then i dont get the new value of my current value. In other words it did NOT changed.