I would like to add some requests:
That tracking the tracking be done by the store owner.
That it is possible to include free addons up to a certain amount and then get the value of each addon chosen (sometimes a product/meal already accompanies an addon. Lunch. + 2 accompaniment, in this case only the third follow-up that would be charged)
Include transparent payment so as not need to go to the payment page (e.g., if you choose paid market, it redirects to the paid market payment page, and it could be done within the application itself)
Include inventory management and API for management of this.