Lua Help with this script

local config = {
    [9172] = {items = {{18402}, {18414, 12}, {18396}, {18500}, {2160, 5}, {18423, 2}}, storage = Storage.QuestChests.WarzoneReward1, containerId = 18394},
    [9173] = {items = {{18402}, {18415, 7}, {18396}, {18504}, {2160, 3}, {18423, 2}}, storage = Storage.QuestChests.WarzoneReward2, containerId = 18393},
    [9174] = {items = {{18402}, {18413, 10}, {18396}, {18508}, {2160, 4}, {18423, 2}}, storage = Storage.QuestChests.WarzoneReward3, containerId = 18394}
}

function onUse(player, item, fromPosition, target, toPosition, isHotkey)
    local useItem = config[item.uid]
    if not useItem then
        return true
    end

    local player, cStorage = player, useItem.storage
    if player:getStorageValue(cStorage) > os.time() then
        player:sendTextMessage(MESSAGE_EVENT_ADVANCE, 'It is empty.')
        return true
    end

    local container = player:addItem(useItem.containerId)
    if not container then
        return true
    end

    for i = 1, #useItem.items do
        container:addItem(useItem.items[i][1], useItem.items[i][2] or 1)
    end

    player:setStorageValue(cStorage, os.time() + 20 * 60 * 60)
    local itemType = ItemType(container.itemid)
    player:sendTextMessage(MESSAGE_EVENT_ADVANCE, 'You have found ' .. itemType:getArticle() .. ' ' .. itemType:getName() .. '.')
    return true
end