[python] Add menu in left toolbar

Software Natron
1

Hi, I tried to add menu to the left toolbar

Add to the top menu is a very simple
from NatronGui import *

NatronGui.natron.addMenuCommand("Custom/ReloadReaders", "initGui.reloadSelectedReaders", Qt.Key.Key_R, Qt.KeyboardModifier.ShiftModifier)

But I cann’t find how add menu to the toolbar?

Thank you