To create a coupon, proceed to Setup > Reductions > Coupons > Select "Add"

-Give Coupon a name

-Select "Lookup..." and pick a location on the screen for that coupon (How it will display on FOH; MANDATORY) 

-Max Amount: Max amount this coupon will take off of per coupon use

-Min Check: The minimum a check total has to be for coupon to apply

Under rates tab, you input the percent per item type that the coupon will apply to.

Under taxes you have the option to:

-Reduce Tax

-Customer Pays Tax

-House Pays tax 

You also have the ability to set "Times" for the coupon use, select the items the coupon only apply to or doesn't apply too under "Items" tab, and "Auto" apply to items when selected on FOH.