At the bottom of Video Studio, you'll see a drop-down selector. SND has several pre-loaded royalty-free music options that you can use in your video.
If desired, you can select "Add Custom Media" at the bottom of the list to upload your own audio track in MP3 format.
Instagram audio bitrate is recommended to be less than 128kbps.
Preview your audio and video by clicking the "Preview" button at the bottom of Video Studio.