How to create a QList<CustomClass> data from QMetaType and QVariant？

I have a similar issue now, but I am serializing and deserializing for Q_GADGETs.

This is my question on StackOverflow
https://stackoverflow.com/questions/78184106/how-to-create-a-qlistcustomclass-data-from-qmetatype-and-qvariant-in-qt

This is a snippet of my example code on GitHub.
https://github.com/zshuaia/test_qt_serialize