Once a coupon is created, only the Redemption limits can be changed. The Coupon Code and Applies to cannot be edited. If you need to change, you'll want to recreate a new coupon(make sure to keep the
Navigate to Marketing > Coupons and click Add Coupon. Title your coupon and choose the discount amount, which type of content it applies to and whether it expires or has a certain amount of redemptions.
Note: If you need to create a large number of coupons (20+) see here for what to submit to our support team.