Hi,
I'm not sure what you mean ?
If you want to add new columns of information in either the "hikashop_order" table (tied to the order), you can create custom fields of the table "order". Then, if the name of your input corresponds to the name the custom field would use and that you replace the display of the custom fields by your HTML, you can have the save of the fields view of the checkout workflow save all your data automatically.
For the "hikashop_order_product" table (tied to the products in the order), there is no save in the checkout for that information so that means you would have to handle the saving yourself.
I would personnally recommend, you add your columns in the tables yourself and develop a plugin to add a new view to the checkout workflow with the "checkout API" of HikaShop:
www.hikashop.com/support/documentation/6...tation.html#checkout
That way, you can handle the display and the saving of the data yourself through the plugin.