Lua 10.99 store check free capacity

[Shadow Dan]

Need some help with script.

If i buy something in shop without capacity it removes coins and no item will be added.
If i have capacity for like 44 runes and i buy x250 i will get only 44 and lose coins.

I wonder how to add check player free capacity for item that we are buying (example 250 runes or only 1 item).
There is loop for adding item and that makes it hard for me.

        -- If offer is item.
        if offer.type == GameStore.OfferTypes.OFFER_TYPE_ITEM then
            local inbox = player:getSlotItem(CONST_SLOT_STORE_INBOX)
            if inbox and inbox:getEmptySlots() > offer.count then
                for t = 1,offer.count do
                    inbox:addItem(offer.thingId, offer.count or 1)
                end
            else
                return addPlayerEvent(sendStoreError, 250, player, GameStore.StoreErrors.STORE_ERROR_NETWORK, "Please make sure you have free slots in your store inbox.")
            end
        -- If offer is Stackable.
        elseif offer.type == GameStore.OfferTypes.OFFER_TYPE_STACKABLE then
            local inbox = player:getSlotItem(CONST_SLOT_STORE_INBOX)
            if inbox and inbox:getEmptySlots() > 0 then
                local parcel = inbox:addItem(23782, 1)
                local packagename = ''.. offer.count..'x '.. offer.name ..' package.'
                if parcel then
                    parcel:setAttribute(ITEM_ATTRIBUTE_NAME, packagename)
                    for e = 1,offer.count do
                        parcel:addItem(offer.thingId, 1)
                    end
                end
            else
                return addPlayerEvent(sendStoreError, 250, player, GameStore.StoreErrors.STORE_ERROR_NETWORK, "Please make sure you have free slots in your store inbox.")
        end

Example of check capacity.

    if player:addItemEx(reward) ~= RETURNVALUE_NOERROR then
        local weight = reward:getWeight()
        if player:getFreeCapacity() < weight then
            player:sendCancelMessage(string.format('You have found %s weighing %.2f oz. You have no capacity.', result, (weight / 100)))
        else
            player:sendCancelMessage('You have found ' .. result .. ', but you have no room to take it.')
        end
        return true
    end