Edit Playlists
Hi-Fi doesn’t include support for creating, editing, or deleting playlists. You can use Apple Music to manage your playlists, which will then be reflected in Hi-Fi.
Apple Music App
Section titled “Apple Music App”You can manage playlists in the Apple Music app on:
Apple Music on the Web
Section titled “Apple Music on the Web”You can manage playlists on music.apple.com.