You can access the marketplace by tapping on the "Rewards" menu item at the bottom of the screen. In the marketplace, you can explore various retailers and their offers. You can see your balance at the top and you can only buy items if you have a positive rewards balance.
Discover or search retailers by name or category. When you find a suitable offer, tap on their name to see the available products. You can purchase rewards with your points by adding them to the basket and checking out in a few simple steps.