The default invoice template has the following fields visible on its Invoice PDF:

In Settings - Document templates, these fields can now be hidden and you can decide which ones you wish to keep on the invoice.
To hide a field, simply click on the eye (👁️) icon

Here is an example of how an invoice would look with only the description and subtotal (amount) fields:

💡 Hiding fields works both on existing templates, as well as on new templates. Additionally, hiding fields is only supported on Standard and Elegant template designs.svoje neke dizajnove na kojima ovo neće raditi)