The app would start recording only after you turn on the ATC pop ups.
See this step by step video: https://www.youtube.com/watch?v=16v0jgZPvh4
or follow these steps to test it:
1) Enable "Add to Cart" pop ups
2) Save (bottom right purple button)
3) Visit your store and head over to a product page. Click "Add to Cart".
4) Close the window
5) Open your store in a new window
-> See the pop up.