First of all, OX Inventory and OX scripts are only compatible with Qbox and ESX. If you're using QB, many features in OX will not work.
My script handles item usage through the functions ESX.RegisterUsableItem (for ESX) and exports.qbx_core:CreateUseableItem (for Qbox).
Since OX Inventory is not compatible with QB, the item usage functionality will not work in this case.