Discount on some products

-- HikaShop version -- : 4.6.0
-- Joomla version -- : 4.1.4
-- PHP version -- : 7.2.4

Hello everybody,
I'm testing a free version of HikaShop and I'm testing discount management.
I want to select only some products with a discount (example 10%).
The problem is that all products are discounted by 10% instead of the product I set. Where am I doing wrong?

Thank you!