I am finding the score editor like a silly toy. It starts out showing only a treble clef. I found you can go into score > settings and set it for piano and now it will show treble and bass clefs. But it won’t place notes on the bass clef.
You are asking people who like the Score Editor how to use such a silly toy.
I would suggest browsing through the beginning of the Score Editor manual to understand the elements on the screen and how it works. Or browse the Score Editor tag for one of the other many posts asking similar questions.
Okay. It looks like it’s NOT in the Settings page but rather in the panel that you open up in
Right Zone only.
Staff mode = Piano Split.
Together with the settings to show the Pedal in more traditional bracket form… this is actually NOT a toy. Feel much better about this now that I found those.