you see in the right sidepanel a button with 'p' in it. If you click it and click in the mainscreen close to a note. You see the principle working. But it has to be attached to the note, also when zooming in/out. There are 3 types of elements that must be added: 1) simple letters like 'p', 2) graphic elements, like the hairpin <, and 3) 1 textelement (the 'C'-button).
All 3 buttons work, but the elements do not stick to the notes properly when zooming in and out.
Detailed Job subscription and video + jpg as attachment. The first half of the video shows how a graphical element has to be divided when zooming in. You can read about it in the text-document I added.
I am willing to pay higher rates for the most experienced freelancers