The Voice Note widget is the best way to add audio to any Pod.

This is contained in the Widget panel on the right hand side of the edit Pod screen.

You can record audio directly in the widget itself, or upload an audio file into the widget instead.

See this is action here:

(please note - I am sorry to say that you won't sound like you're at Wembley in your audio recording, that was a quirk with recording via loom)