SAP RAP: Modify ENTITIES in the respond (Unmanaged Implementation)

Hello Guys,

I developped a RAP Service type: “Unmanaged Implementation”

And I would like to modify the ENTITIES values in the respond. Below my POSTMAN request, when I execute it (POST), I want to fill the parameter: “RESERVATION” in the RESPOND.

 

Here my Service Exposition and Method:

 

Here my Business Definition:

Here my CDS:

Here my Behavior Class:

The parameter ENTITIES is defined as IMPORTING. Probably here, I should to modify it as CHANGING or someting else… but it’s not working ?

Any idea?

Best regards,

Rachid