A common promotion is to offer free shipping with a coupon code. 

Follow the steps below to quickly create the promotion:

1. Go to the Marketing > Promotions page.
2. Click Add new.
3. Give your promotion a name. e.g. "Free shipping"
4. Select "Shipping" under Promotion type.
5. Select "Flat discount" under Promotion rule.
6. Enter "100" in the Discount field.
7. Change the discount type to "Percentage".
8. In the Require coupon dropdown, select an existing coupon code or click the New button to generate a random one. You can rename your coupon code later.
9. Save your changes.

If you like to change the coupon name, follow the steps below:

1. Click on the Edit button next to the Require coupon dropdown. You can also find your coupon code from the Marketing > Coupons page.
2. You will be redirected to the coupon page. Change the coupon to your desired code. Remember coupon codes are not case-sensitive. Choose a coupon code that is easy to remember and difficult to guess.
3. Save your changes.