The Studio's default functionality is recording audio/video recordings in the MP4 format. If however, you need audio only in the MP3 format, follow the below steps:

Plug the USB cable into a port on your laptop.

Right click the audio icon in your laptop's tray.

Select "Sounds".

Select the "Recording" tab and select "Black Magic Design" as the default device.

In your Search Bar, type "Voice Recorder" and select the app.

You are ready to begin your recording. Press the microphone icon to start.

You will get a running clock. When you are finished, push the stop button. 

You will have the option to review, go to the file, or start another recording.