When saving a recipe or export a farm, you can see the check “Save also on Dropbox”. This check will allow you to save the file on your local machine and also on Dropbox directly.
Important: to save the file on Dropbox via the NDS option, the file must be saved also on a local folder.
The default folder where the file will be saved is the “File save location” that you set in the Dropbox settings. You can change the folder while saving, clicking on the button next to the check.