PDF-invoices can be downloaded from the application:
1. Go to the license & billing page and choose 'manage plan'. A popup will open.
2. Choose 'edit subscription details' on the upper part of the modal to go one view back.
3. Repeat this step one more time: click on ' <-- subscription details' on the upper part of the popup.
4. This will bring you to an overview. Choose 'billing history' to find all the invoices.