Apple in iOS 14.5 and iPadOS 14.5 added a new option to help Siri learn to select your preferred audio apps for listening to music, podcasts, and audiobooks.
The first time you ask Siri to play music, a podcast, or an audiobook after installing these updates, you will be asked to select your preferred app from a list of those you have installed and which support this feature. Siri will remember your selection and will use that service whenever you ask it to play something. So, for…