Campaigns define the presentation of the reward as well as the catalog items available to recipients (i.e. merchant gift cards, Visa prepaid cards, etc.).
API Order create calls can (optionally) specify a Campaign ID. In addition to simplifying the data passed via the client application, this allows decoupling of the design of the reward from its execution by the developer / application.
Campaigns can be fetched programmatically via the API. IDs can also be grabbed from the dashboard UI.
To do so, first, click on the top level "Order" navigation element.
Next, within the Digital Order section, we'll see a number of Campaigns along with their associated IDs (if no Campaigns exist, you'll need to first create one).