Much simpler.
Skipping the part of unlocking the device, assume it is.
Press
- and hold the side edge MUTE button two seconds.
- Voice assistant opens
- say "record a voice note"
- speak
your voice note.
Should you want to use your own path above, you can move the icon UP on the screen or to the initial icon screen, or even use a third party app to create a KB shortcut.