Fixed price coupon

I tried to make a coupon “2 for ￡20” to be able to add two products with different prices and the total to be a fixed price. The problem is I’d like the discount to be applied also if I add the same product twice, not only one of each product, if it makes sense. Do I have to create different coupons for each scenario? Or is there a way to make it work for all cases to have a fixed basket price?

I have tried changing the settings to percentage basket discount and product conditions: all from below but still got the same result.

Please see following link for system set up and screens:

https://www.ads-software.com/support/topic/fixed-price-coupon-2/#post-16046348

The page I need help with: [log in to see the link]