I’m very sorry for the late reply – your email “drowned” in my inbox.
The easiest method is to look at the “Enhanced with DFFS” link below the form – hover over it and click “License and version information”. If you don’t see this option, you have an older version. If so, you might be able to bring up the developer console (hit F12 > Console) and type in this and hit Enter:
If none of the above works you can also see the version of the Backend of DFFS when entering the backend configuration – it’s show in the top of the screen.