How to implement these market activity?

Hi,

HikaShop doesn't allow for such discounts/coupons.
You can select a product, or several products, and a minimum quantity, but the discounts/coupons will be valid regardless of whether the customer purchase 2 A products or 1 B and 1 A products. To say that you want to allow the discount only for 1 A and 1 B, you can't do it with the options available by default.

There are two solutions you can investigate:
1. Create a HikaShop plugin implementing the "coupon" or "discount" APIs:
www.hikashop.com/support/documentation/6...entation.html#coupon
That way, you can enforce whatever rule you want for the coupons/discounts
2. Look at AWOCoupon:
awodev.com/products
It's compatible with HikaShop and has much more options for complex discounts like you need.