How to save a text file on a Quest 3 with UE 5.5?

I created an app that need to save data as JSON in a text file, with a custom extension. In blueprint I use the "Save Json to File" node, and with "Make File Path" I create a file path using "Get Platform User Dir" as a folder. It works on Windows, saving to Documents folder, and it worked on Quest 1, saving to the app data folder. 

Now I've ported my app to UE 5.5 and Quest 3, and I can't save anymore, I get an error. 

I searched a lot but can't find any information. What should I do to save a text file on the Quest 3 device in an app developed in UE 5.5?