DataStore will not save the items in my table, what did I do wrong?

So I'm working on a skin shop in my game. But for some reason my Data Store will not save my table that I've created with the object models of the skins. Here's my error message

DataStore Error: 35: invalid argument #1 to 'pairs' (table expected, got string)

local dataStoreService = game:GetService("DataStoreService")
local TokensDataStore = dataStoreService:GetDataStore("Tokens")
local WinsDataStore = dataStoreService:GetDataStore("Wins")
local InventoryDataStore = dataStoreService:GetDataStore("Inventory")
local http = game:GetService("HttpService")
game.Players.PlayerAdded:Connect(function(plr)
    local leaderstats = Instance.new("Folder",plr)
    leaderstats.Name = "leaderstats"
    local Wins = Instance.new("IntValue",leaderstats)
    Wins.Name = "Wins"
    local Tokens = Instance.new("IntValue",leaderstats)
    Tokens.Name = "Tokens"
    local Plr = Instance.new("Folder",game.ServerStorage:WaitForChild("PlayerInventory"))
    Plr.Name = plr.Name

    local WinsData
    local TokensData
    local InventoryData

    local success,errormessage = pcall(function()
        WinsData = WinsDataStore:GetAsync(plr.UserId.."-Wins")
        TokensData = TokensDataStore:GetAsync(plr.UserId.."-Tokens")
        InventoryData = InventoryDataStore:GetAsync(plr.UserId.."-Inventory")
    end)
    if success then
        Tokens.Value = TokensData
        print(TokensData)
        Wins.Value = WinsData
        print(WinsData)


        if InventoryData then
            print(InventoryData)
            print(tostring(InventoryData))
            for i,skin in pairs(http:JSONDecode(tostring(InventoryData))) do
                print(skin.Name..": hi")
                local playerInventory = game.ServerStorage:WaitForChild("PlayerInventory")
            end
        end
        print("Loaded data.")
    else
        warn("DataStore error: ",errormessage)
    end
end)

game.ReplicatedStorage.events.ServerTokenUI.OnServerEvent:Connect(function(plr)
    local tokens = plr.leaderstats.Tokens
    game.ReplicatedStorage.events.ClientTokenUI:FireClient(plr,tokens)
end)

local bindableEvent = Instance.new("BindableEvent")
game.Players.PlayerRemoving:Connect(function(plr)
    local success,errormessage = pcall(function()
        WinsDataStore:SetAsync(plr.UserId.."-Wins",plr.leaderstats.Wins.Value)
        TokensDataStore:SetAsync(plr.UserId.."-Tokens",plr.leaderstats.Tokens.Value)
        local skins = {}
        local inventory = game.ServerStorage.PlayerInventory[plr.Name]
        for _,skin in pairs(game.ServerStorage:WaitForChild("Skins"):GetChildren()) do
            if inventory:FindFirstChild(skin.Name) then
                table.insert(skins,skin)
                print("Added: "..skin.Name)
            end
            print(skin)
        end
        InventoryDataStore:SetAsync(plr.UserId.."-Inventory",http:JSONEncode(skins))

        if #game.Players:GetPlayers() <= 1 then
            bindableEvent:Fire()
        end
    end)
    if success then
        print("Saved data.")
    else
        warn("DataStore Error: ",errormessage)
    end
end)
game:BindToClose(function()
    bindableEvent.Event:Wait()
end)