Creating A New Payment Method

I’m trying to create a new payment method following the instructions at [url=“CS-Cart Documentation — CS-Cart 4.16.x documentation”]CS-Cart Documentation — CS-Cart 4.16.x documentation. I’m an experienced developer and reasonably familiar with Smarty

This payment method requires a new template to collect specific data, but I cannot find any instructions as to how to go about this. If I create a new blank template in


for example xxx.tpl, then set the template field in the cscart_payments to hold


The system gives me an error when the new payments method is clicked on. However if I specify the, also empty, cod.tpl template in the field then I get now error, just a blank field.

There appears to be no additional documentation so far as I can see that discusses how to implement this, and I can’t spot any other tables that would appear to be relevant.

How do I fix this? And how do I process new data fields?