Creating a chord in the current score

Hi!
I am trying to create a chord, add new notes to it, and then insert it in the current score, at the user's cursor position. (if possible)

Here is what I have, so far:

https://github.com/aalex/jazzChord/blob/master/jazzChord.qml#L58

In the documentation, it says that one should be able to create a new Chord. https://musescore.org/fr/plugin-development/chord-object
I have this error message in the console:

58:-1: ReferenceError: Chord is not defined

Any idea why? How can I create a chord, and insert notes to it? (I would rather use the Harmony type, too, so that I can insert a Cb instead of a B, depending on the tonal context)

Thank you!