You must first create the promotional offers in the software in order to appear within an app:
Go to the "Sales Tool".
Click on the "Coupons".
3. Add Coupon Name, Coupon Code and Coupon Offer >> Discount Percentage.
4. Select whether its One Time Used or Multiple Time and how many of your customers can redeem this.
5. Add the Expiry Date and Click on the SAVE.
The promotional offer will appear in the application under the Offer button when you have saved it.