When create a new order for customer I want to have a text box to enter the “custom discounts” for that particular order in admin panel => sales=>create order without affecting the tax (minus directly from the grand total). I was able to apply a custom discount module by code. However, I failed to pull it out to the user interface to be able to edit for a specific order. Can anyone give me some advices on this please. Thank in advance.
p/s: English is not my main language.
This is an example:
Need a text box to edit the “Custom discount”
Custom Discounts: -$22.50
Grand Total: $897.00