Administration in Run-Time Only APEX

Simple, but you have to know...

connect system
alter session set current_schema = FLOWS_030100;

begin
 apex_instance_admin.set_parameter('PRINT_BIB_LICENSED','ADVANCED');
apex_instance_admin.set_parameter('PRINT_SVR_HOST','tobi01.home.local');
apex_instance_admin.set_parameter('PRINT_SVR_PORT','8123');
apex_instance_admin.set_parameter('PRINT_SVR_SCRIPT','/xmlpserver/convert');
apex_instance_admin.set_parameter('PRINT_SVR_PROTOCOL','http');
end;
/

The doc states you have to have a session as sysdba, but system works for this version, too.