Hook f'Thank you for your purcahor post checkout order with total payment of $0

Hi,

No worries. Note that even if you can't update Joomla, the latest version of HikaShop is still compatible with Joomla 3.
However, it's a big update as many things changed in HikaShop. So if you plan on updating HikaShop in the future, I would recommend first testing on a copy of the website.

Regarding the issue at hand, I can say for sure, but normally, when an order is created, the onAfterOrderCreate event is triggered:
www.hikashop.com/support/documentation/6...l#onAfterOrderCreate
So, you should be able to implement that event and do your processing in it. Not that this event will be called for all the "hikashop" and "hikashoppayment" plugins. So you could potentially directly implement it in that custom payment plugin, even if the payment plugin doesn't handle the payment. Note also that you'll want to change the order_payment_method since you probably want to not do the house keeping at the order creation step when the payment plugin is used for the payment (since it will be done later on, in the onPaymentNotification method).