If you wish to provide your clients with a discount/promotion for when they are purchasing your Services (packages, memberships or products), you can do so by following these steps below...
Creating a discount/promo code for a service
In your Services area, head to either the Packages, Memberships or Products tab, then edit an existing item or add a new one.
Turn on the 'Discount/Promo Codes' switch. This will present you with more options where you can create your promo code and applied discount %. You can also limit how many times a discount code can be used by each client for this particular item.
Redeeming the discount/promo codes
As a Client:
Your clients will be presented with the 'Apply discount' option while purchasing an item from your Client Area's Store. This is also supported through the Mobile Apps. Client example:
As a Trainer/User:
While assigning any service to a client, the trainer can optionally apply an existing discount code at the same time, example: