Opening the "Promotions Setup" page shows a few fields you can configure to apply additional settings when using the Clever Promotions app.
Enabling the field Apply Promotion on Release will apply the promotion that best fits the "Sales Order" when the Status is changed from 'Open' to 'Released' automatically.
Within the Promotion No's dropdown, you can define the "No Series" you wish to use when creating new Promotions. You can find more information on creating promotions here.