Hi Carlo,
To raise a credit note you’ll need to switch back to our ‘Classic’ view. To do this, go to the ‘Sales > Invoices’ section and click the toggle at the top of the page. Now, click on the ‘Options’ button and you’ll see that you can choose either ‘Raise Credit note’ or ‘Raise full credit note’, depending on if you need to add a partial or complete credit note.
The option to add credit notes via our Beta invoicing will be coming soon.
Hope this helps.
Katie