There is currently no QML-way to make a scrollable item. QtQuick offers Flickable, QtQuickControls offers ScrollView. Which one (or maybe even another one) is the best choice?
This project is unfortunately no longer maintained. If a new maintainer wants to step up and take care, the project is archived here: https://invent.kde.org/unmaintained/qmlweb You can just clone it in your private namespace on invent.kde.org and if you have started to work on it and fixed/implemented something get it reviewed and the project unarchived. Sorry for the inconveniences.