Go to Woocommerce > Discount Rules in your dashboard.
Click ADD NEW RULE button to add a new Rule Setting.
Once you have finished setting up the rules, click the SAVE & CLOSE button.
Example: Buy Moisturizer A + Cleanser B and get Sunscreen C for FREE.
This example offers customers a free product (Sunscreen C) when they purchase a combination of two other products (Moisturizer A and Cleanser B).
RULES SETTING:

WEBSITE VIEW:
Once this rule is implemented, customers who purchase both Products A and B will automatically get Product C as free (as we have set the free quantity as 1 and chosen the mode of apply as autoadd). The Free Product will get automatically added to the cart page, as shown in the screenshot below.
