Hi there, @Mijel. 

Welcome to the Community. Please allow me to join the thread and help share information about Journal Entry. If you don't desire to use any app, you have to manually enter the journal entry transactions and input all the details needed. 

On your second question, importing journal entries to QuickBooks directly is unavailable. We need to use a 3rd party app that integrates with QBO.   

Though, you may want to consider checking the lists of supported Third-Party app in QuickBooks. 

In the meantime, please check our blog site to know the latest update of QuickBooks. Here's the link: The QuickBooks Blog. 

Please know that the Community is always here to help you out. Just click the Reply button, and I'll get back to you. Have a great day!