For Android:
https://help.playbackbone.com/hc/en-us/articles/9691763865623-Do-I-have-to-remove-my-Android-phone-from-its-case-to-use-a-Backbone-One-
For iOS:
https://help.playbackbone.com/hc/en-us/articles/4405915639447-Do-I-have-to-remove-my-iPhone-from-its-case-to-use-a-Backbone-One-