Apply voucher code for products which are already reduced and apply a greater percentage off (Prestashop 1.6)

[pinguluk]

Hi!

 

I have some products which are on sale with 0% - 14 % off and I want to add a coupon code, that will change them to 15%, when entered.

Example: I want to buy some shoes that are 5% off, some pants that are 10% off and a t-shirt with 40% off.

When I will enter the coupon code, the shoes will be 15% off, the pants will be 15% off too and the t-shirt will remain 40%.

 

How can I achieve that? Is there any module? Or I have to change something in the code?

Thanks!

Edited August 5, 2020 by pinguluk (see edit history)