What is the private key I need to upload?

When I try to open my form it asks for a private key. I don't know what that is.

Encryption is currently enabled in your form: 

It will not be possible to de-crypt the data, unless you provide the key, if you have not moved it, then it should be saved in the default folder, the downloads folder, if you're using Windows then follow these steps: 

On your Windows computer, it is most likely in the downloads folder, so all that you need to do to access it, is to type this into address bar:

%HOMEPATH%\Downloads



or click on Downloads on the left part of your Explorer

If you are a Mac user, you can simply click here:

If the key was not moved then it should be found there, otherwise will not be possible to de-crypt your data.