Insert a horizontal line below system

Hi, I'm trying to insert horizontal lines below the note systems. Something like "Pedal" or "Line" in the palette. But I don't know how to create them with plugin code. I tried:

let e = newElement(Element.TEXTLINE) // Element.PEDAL also works

I got/guessed the element types from here.

Looks like these span elements can somehow connected to start and end chords. But before I fiddle around for hours, can someone give me a hint?

• Of which class is the line of element type PEDAL/TEXTLINE?
• Do I have to call startChord.add(e); endChord.add(e) or where do I have to add the line?
• Is there anything else to consider?