You must add the Rewards store (if it isn’t already) and allow ordering for Reward Point inventory items.
Read more: Adding Stores
Steps specific to Reward Points setup:
In Corporate Office, navigate to Inventory > Manage Stores.
Locate the Rewards store in the list.
In the Allow Ordering column, there should be a icon.
If Allow Ordering is unchecked:
Click the Edit button.
The Edit Store pop-up window opens.
Select the Allow Ordering checkbox.