How to set draft AuthorizationStatus

I have successfully created a draft using DI API but I'm failing to set its authorization status to pending as it is read only. It actually inserts with no status and the problem with this is that when I create the draft it appears as a preliminar draft (in SAP client) and someone has to "manually" create it.

Any ideas on how to approach this? Is there any way to set the authorizationstatus? Or to trigger some procedure that changes its value?

Thanks in advance.