Hi again, dani_rodri. 

The file extension for Journal Entries are .QBJ. If you're trying to import journal entries into your account, you can have your accountant send you a General Journal Entries file with a .qbj extension. From there you'll be able to have your person upload them into your QuickBooks account. 

You can refer to this article for additional information on Journal Entries and how they work: Use journal entries to adjust your client's books.

Thanks for your time and have a nice evening.