How to set authorDisplayName to the correct author in MusicKit Swift?

I'm creating playlists in iOS 16 with the following code:

let playlist = try await MusicLibrary.shared.createPlaylist(name: caption, description: description, authorDisplayName: nil, items: items)

I want to set the authorDisplayName to the current user, who used my app to curate the playlist. How can I do this?

Looking at playlists in the Music app which were created using the Apple Music API the user's name was being defaulted automatically. But I can't seem to replicate this using MusicKit: I can't explicitly set the name as I don't think it's exposed to me, and if I set it to nil or empty then I get my app name, not the user's name.

Thanks in advance.