ServerScriptService.ShopModule:9: attempt to index field 'OreMaterial' (a nil value)?

This is the module Script

function Shop.Sell(player)
    local Ore = Shop.OreName
    if player.OreMaterial[Ore].Value >= OreMod[Ore].price then
        player.leaderstats.Money.Value = player.leaderstats.Money.Value * OreMod[Ore].price
        player.OreMaterial[Ore].Value = 0
    else
        print("Nothing to sell")
    end
end

I get an error: 15:47:35.845 - ServerScriptService.ShopModule:9: attempt to index field 'OreMaterial' (a nil value) if player.OreMaterial[Ore].Value >= OreMod[Ore].price then is the part I need fixed

This is inside the LocalScript

local player = game:GetService("Players")

function SellStone()
    game.ReplicatedStorage.LevelUp:FireServer( "Stone")
end

script.Parent.SellStone.MouseButton1Click:Connect(SellStone)

and this is the script where I access my RemoteEvents

function SellOre(player, Ore)
    ShopMod.OreName = Ore
    ShopMod:Sell(player)
end