[Your Block] saved to Audio category should have at least one audio element.
To save an Audio block, you need to be sure that the proper element is incorporated into the block. To do this, simply go into the Audio Block you’re trying to save and click on the + button to open up the Elements page. From here, click on the Elements category and add the Audio element to your block. This will allow you to embed a song from Spotify or Soundcloud; you can also just enter a song's URL.
The audio element comes with 1 EM of padding all around, but you can adjust that in the Margin & Padding option of your layout panel.
You can also utilize our block library and add one of our foundation audio blocks to fit your page style.