We are an audio device manufacturer, we would like to integrate the MusicKit (Apple Music API) in our app, allow the users to login their Apple Music account in our app, browse and play music from the app, and cast the music to our audio device. To enjoy Apple Music on the Hi-Fi audio systems. Is the MusicKit (Apple Music API) applied to this scenario? Do we need a license agreement to use the MusicKit and Apple Music API? Do you require royalty for the licenced devices? Thanks for taking the time.