To create coupon navigate to Seller Dashboard -> Coupon then click on the “add new coupon” button. Insert name, type, products you want the coupons to apply to, then click on theadd coupon button.

Fixed Amount Discount coupon means when a buyer uses the coupon he will get a fixed amount discount off his total cost.
 

Product Percentage Discount means when a buyer uses the coupon he will get a discount depends on the percentage mentioned on the coupon.