Intercompany Billing for Non-Shippable Service Items in Order Management

Hi Team,
We are looking for the best practice to handle intercompany transactions specifically for Service items (non-shippable) within Oracle Cloud Order Management.

Scenario:
Business Unit A (Selling BU): Creates the Sales Order for a service (e.g., Consulting, Installation, or Maintenance).
Business Unit B (Service Provider BU): Actually performs the service and holds the costs.
Requirement: We need to demonstrate this in Oracle fusion and need to understand the required steps

Challenges:
Since these are service items and do not involve a physical shipment or warehouse "ship-confirm," we are unclear on what event triggers the Supply Chain Financial Orchestration (SFO) flow.