In Promotion Rule, navigate to 'Ledger Transaction' section to connect the purchase of the product with this promotion rule to a specific omniLedger Account.

Learn more on how create accounts in omniLedger.

When Promotion Rule is synced to the omniLedger, every time the order is created with this Promotion Rule, the corresponding Ledger Account will have a transaction with information about this promotion and link to the order.