Set main finger 4 ⌃⌥⇧4
With the Score Editor open you bring up the Staff Style panel (⌃⌥⇧S) and change the “Head” setting to “Finger”. Choose the finger number that you want to apply and click on the note head.
Set the appearance of note heads: Choose a value from the Head pop-up menu. You can display note heads as normal, show note names or finger names, or hide the note heads completely.
⇧ SHIFT – ⌃ CONTROL – ⌥ OPTION – ⌘ COMMAND