On all 3 upcoming checkout pages (Information > Shipping > Payment), there is a box that says "gift card or discount code".
Enter the discount code in the "gift card or discount code" box.
Make sure you click "apply".
Remember that free shipping is available when your total AFTER the discount is applied is $50 or more.
On a desktop it will look like this:
On a phone it will look like this:
Join the Goat Milk Stuff Family
Want to receive discounts and special offers? Become a part of the GMS family and you'll stay up to date with all the latest news. We'll even throw in some cute baby goat photos every now and then.