How to not display string numbers in chords

[Grateful Frog]

Hello again!

I'm once again posting with a newbie question.

I'm trying to make a score with both music and tab staffs, as well as chord names a fret diagrams. But NOT string numbers in circles.

Can anyone suggest the proper thing to set? Is it an override?

My Score section looks like this:
\score {
  <<
    \new ChordNames { 
      \mychords 
    }
    \new FretBoards { 
      \mychords 
    }
    \new Staff  { 
      \myTempo
      \myKey
      \override Staff.TimeSignature #'style = #'()
      \myTime
      \mynotes
    }
    \new TabStaff  {
      \override Staff.TimeSignature #'style = #'()
      \myTime
      \stemDown
      \override Beam #'damping = #+inf.0
      \mytabs
    }
  >>

Thanks for any help!
Cheers,
GF

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