Dear colleagues,
I am working with a custom extension of stabdard service API_SALES_ORDER.
As I can see, the creatable flag is disabled for entityset A_SalesOrderItemText

How to make it creatable?
I have tried to write such code into define method of MPC extension class but it did not help
DATA(lo_entity_set) = model->get_entity_set( 'A_SalesOrderItemText' ).
lo_entity_set->set_creatable( abap_true ).
Could you suggest how to make a entityset creatable?