A quick look at the documentation revealed that in case of RichTextLabel, you can call
get_v_scroll(), which should give you VScrollBar object. You can then call
VScrollBar.set_value(0.0). Another way would be to call
I don't know if ItemList provides it's own scroll bar (I didn't use it so far) but because it looks it doesn't, I would try to put ItemList in ScrollContainer and then call
ScrollContainer.set_v_scroll(0). I didn't test the code but it should give you a good idea how to scroll those nodes.