Why does this Dev Product script not give "value" when purchased? [closed]

Hey, there!

Thank you for wasting your time out of your day and clicking onto this to maybe help me with this script.

What I'm trying to make is a Dev Product that will give the user (when purchased the product) some leaderstat "strength". My stats handler is located in ServerScriptService, and then there is a folder "plr" with all the intValues in it, such as Strength, etc.

The problem is though, that I cannot get the script below to work.

I also do have another script which connects this with a TextButton in order to prompt the purchase to the user. (Which works as it prompts the user, just doesn't give the user 5 Strength when the user purchases the Dev Product).

Would anyone know why it doesn't give the user 5 Strength in their stats when purchased the Dev Product?

Thank you so much for reading and I will appreciate any help anyone is willing to give!

Script:

local MarketplaceService = game:GetService("MarketplaceService")
local ds = game:GetService("DataStoreService"):GetDataStore("PurchaseHistory")

CASHID = 1135295617

    MarketplaceService.ProcessReceipt = function(receiptInfo)
        local playerProductKey = "player_" .. receiptInfo.PlayerId .. "_product_" .. receiptInfo.ProductId
        local numberBought = ds:IncrementAsync(playerProductKey, 1)
        for i,v in pairs (game.Players:GetChildren()) do
            if v.userId == receiptInfo.PlayerId then
                if receiptInfo.ProductId == CASHID then


                    lds = v:FindFirstChild("plr")
                    if lds ~= nil then
                        cs = lds:FindFirstChild("Strength")
                        if cs ~= nil then
                            cs.Value = cs.Value + 5
                        end
                    end
                end
            end
        end
        return Enum.ProductPurchaseDecision.PurchaseGranted    
    end