How to create IC Internal Usage entries from an external system in SAGE?

Question

I'm building a business application to manage inventory requisitions. The application is a lightweight web interface used mainly by our internal employees to submit inventory requisitions. The requisitions will pass through a workflow of activities, mainly for validation and approval, and finally, an IC Internal Usage entry should be created in Sage by the application before the requestor can receive the items.

Surprisingly, the Sage web API provides endpoints to create and retrieve almost all types of IC transactions except Internal Usage. I can't understand the rationale behind that, yet I'm looking for a way to create (and post) Internal Usage entries externally from my application, and I'm not aware of any solution for this.