Nikon Z 9 Reference Manual page 478

Custom Settings menu option
f3 [Custom controls (playback)]
[Fn1 button]
[Fn2 button]
[Fn3 button]
[Fn button for vertical shooting]
[Protect/Fn4 button]
[OK button]
[Audio button]
[QUAL button]
[WB button]
[Vertical shooting multi selector]
[Main command dial]
[Sub-command dial]
[Video record button]
f4 [Control lock]
[Shutter speed lock]
[Aperture lock]
[Focus-point lock]
Defaults
478
[Frame advance]
[Video playback]
[Frame advance]
[Video playback]
Default
None
None
None
None
Protect
Zoom on/off
Voice memo
Rating
Select for upload to
computer
Unswitch
1 frame
10 frames
1 frame
10 s
None
OFF
OFF
OFF