discount a different fixed price for each eligible product in the minimum quantity campaign

The customer can choose 3 different products from the collection at different prices and can receive a fixed price discount. For example in my store I have these products

t shirt 15 usd (1 single piece)

Hat 10 usd (1 single piece)

shoes 25 usd (1 single piece)

I want that when the customer selects those 3 products, it generates the following discount in the cart

T shirt 12 usd

hat 8 usd

shoes 20 usd