You can select external storage or a different directory for your recordings. To do that:

1. Go to Settings > Folders and Files.
2. Tap “Folder”
3. Navigate to an existing path (it should look like /storage/9C32-6DBB/voix for the external microsd), or create a new folder for recordings.
4. The app will then ask you to confirm the path. Go to the same folder and choose it.

In Android 4.4 KitKat, access to the external storage is restricted by the system. So you need to unlock that functionality firstly.