Storage Variable with Child [Solved]

I want to save a Variable Structure with Childs to a Storage; I know that there is a “simple” way to do it converting the variable to JSON but I don’t know how to do it and I haven’t found examples in the wiki or anywhere else.

Can someone give me a simple example with the events to do it? To save and load?

To save, the event action is :

To load, the actions are :