At the request of @catsarisky I started with saving data to file.
It works OK from the browser and from Web Test but crashes on mobile Live Test.
I need to do some testing.
The vCard part is very easy.
This is my test project to save a file
https://x.thunkable.com/projectPage/60a172a49d5e640011cd9947
I’m now running the html file from web viewer. I will test running it from open link to check if it works from the mobile app.