We are using the official Apple Music API to get your Apple Music datas and also moving your playlists and favorites to this platform.
Unfortunately, Apple has removed "Delete" methods from his API, that means we are no more able to delete tracks in a playlist or delete a playlist.
That's why you got an error 104 "Feature not available for this platform" if you are syncing with a "Replace" method or using any "Replace to" feature for example.