How to calculate the cost of promotional codes and gifts?

Question

Google Analytics

Hello. Is there any way to calculate the cost of used promotional codes for discounts and gifts for orders? All the reports and options that I found show either just the number of promo codes and gifts used, or in Google Analyticscs you can see a report on the amount of orders using coupons. But nowhere are there options to see how much of these discounts and gifts were distributed. Since a discount and a gift are an expense, I would like to take them into account in the analytics.

Ps. Of course, you can manually count all orders using promotional codes, comparing them with all gifts, but pulling out the numbers automatically would be preferable. Especially when it comes to volume.