Do you mean copy the created mp3 files from the app to your computer?
That depends on the device you have the app installed on.
You then need to find the location the mp3s are exported /saved to on the device and copy them across to your PC.
Note - at this time there are very few users here using the app software so you may have to do a lot of the digging yourself to find the locations files are stored in on your device, referring to the devices manual or user forums may help.