How to save an Array as Json

I created a Json(VisualArray), and using AJAX I put it in a real Array, which I use in my game.

The problem is how to transform this Array back into a Json and save it in the original file.

I'm using WebView2, so I have access to my JSON file in the www folder. I believe I can do this using FileSystem, but I was not successful.

Here's what I did, did I miss something?

I'm able to save now, in the example I'm using the Documents folder:

The problem now became how can I load this saved file into documents..

I was thinking about a logic to check if the file exists, if it exists it loads it into the Array, if it doesn't exist, it uses AJAX and loads the "Clean Array"

However, I don't know which expression to use, AJAX would load the latest data, but the filesystem doesn't have that choice.

I did it, I did it, I feel like Christopher Columbus haha

the solution: