To add audio, create a content item, select the Media layout, and choose the Single audio content block. You can upload new audio files from your computer or add them from Audio Library. Moreover, you can customize the look of the player (select if it will be player only, the player with title, the player with image, or the player with title and image).
You can add and resize a picture from your PC, from the stock, or from your account library.
Supported audio formats
If your audio has a different format, you can convert it to one of the supported formats using free online tools such as media.io, Online Audio Converter, etc.
Check out Audio Upload Guidelines for more details.