The Custom Ringtone is a feature available in the Item Settings of your TrackR app. By selecting "Customize Ringtone," you can choose the song you would like your phone to play when you either ring your phone from your TrackR or when using Separation Alerts. Please note that this song or ringtone must be owned by you and downloaded from your media library, it cannot be chosen from a subscription service like Pandora or Spotify. If the TrackR app asks for access to your media library, it is related to using this feature.
It is important to note that Custom Ringtones is only an option for the phone's ringing. The TrackR's ringing cannot be changed, either in tune or volume.