You can create a discount from the EasyGift rule page to match the criteria set on the rule. The action product can be discounted by either a Shopify promo code or automatic discount.
Here are the steps needed to create the discount from the rule page:
You should set the trigger, action, schedule and targeting on the rule to do what you want the rule to do.
The most robust method to discount the action product is to use a Shopify Automatic discount. However, the promo code method is a good alternative should you want to use that instead.
In the Discounts section of the rule page, select the discounting method you want to choose and click on 'Create new'.
Clicking on 'Create new' opens a modal where you can configure the discount to work with the rule, you can choose between discounting the action product by a fixed percentage (any value between 1 and 99%) or make it completely free. Once you've finished configuring the modal, click 'Continue'.
Confirm this works to how you initially planned by testing on your store.
Rules that use products or collection with selling plans can't use a discount since Shopify does not support this.
This feature may not work on old rules. If you can't see the create buttons in the Discounts section you should recreate the rule and then create the discount from the new rule.
When a discount is set up using EasyGift for a rule using a cart value trigger, EasyGift creates a private collection (it is not published to your storefront - your customers will not see this collection) in the backend of your store containing all products in the store. You should not delete this collection - it is used by the discount.