Upload data from internal memory to Dropbox

I have been trying to upload xml data from the internal memory of my android phone to Dropbox. However, it only works when I use a virtual device. I currently believe that it is because the phone isn't rooted (i.e. I can access /data/data/appname/files in the file explorer for the virtual device but not the android phone) which is required to access the app's allocated internal memory. Is there a way to do this without rooting the phone?