Why my script won't detect the change in the string value?

LocalScript

local UIS = game:GetService("UserInputService")
local NPC = workspace:WaitForChild("NPC")

local event = game.ReplicatedStorage.Substract
local CurrentNPC = game.ReplicatedStorage.CurrentNPC

local player = game:GetService("Players").LocalPlayer
local char = player.Character or player.CharacterAdded:wait()

local maxDistance = 10

UIS.InputBegan:Connect(function(input)
	if input.UserInputType == Enum.UserInputType.Keyboard then
		if input.KeyCode == Enum.KeyCode.E then
			if UIS:GetFocusedTextBox() == nil then
				for i, v in pairs(NPC:GetChildren()) do
					local mag = (v.HumanoidRootPart.Position - char.HumanoidRootPart.Position).magnitude
					if mag <= 10 then
						CurrentNPC.Value = v.Name
						event:FireServer()
					end
				end
			end
		end
	end
end)

Server Script

local event = game.ReplicatedStorage.Substract
local NPC = workspace.NPC
local currentNPC = game.ReplicatedStorage.CurrentNPC


event.OnServerEvent:connect(function(player)
	local stats = player:WaitForChild("leaderstats")
	local present = stats:WaitForChild("Presents")
    if present ~= nil then 
       if present.Value >= 1 then
		present.Value = present.Value - 1
		print(currentNPC.Value)
		end
	end
end)

When I print(currentNPC.Value) which is in the ServerScript, it just prints blank. But when I checked the value for the CurrentNPC in the ReplicatedStorage it is the name of the NPC for example "Test". When I print the currentNPC in the LocalScript it does show the name of the NPC.