When setting up a new reward, you can pick between three types of discounts. The first two are a specific $ or % off the order. However, the third is a fixed price which can be a bit more complicated. For a fixed price, whatever product the discount is applied to will then take on the new fixed price that is set under the reward.
Use Case: An example of this would be a promotion that if a customer buys 4 pre-rolls then they get the 5th pre-roll for $5. To go about creating this discount we need to identify what conditions are required. For this specific example we would need to set the "Applies to" condition to Item. Next, we need to make sure the "type" is set to Fixed Price, with this we also need to set the fixed price under "Amount" to $5. In addition to these conditions, we would also have to set the "product type" to Pre-Roll. Lastly, to ensure this is only applied if 4 pre-rolls are purchased set the "minimum quantity" to 4.