Hi Rodrigo,
For output type determination, you will also need to set up the master data for output type condition record for your output to be determined automatically, whether it has been configured as an item or header output type.
You may check this menu path for reference of the transaction codes for output type condition record maintenance. SAP menu --> Logistics --> Sales and Distribution --> Master Data --> Output.
If you want your output types to be determined automatically, you may use dispatch time/date - '4' [Send immediately (when saving the application)].
Hope this helps.
iessa