You can play MP3 files on an iPhone using four methods: the Files app for direct playback, Apple Music to sync files from a Mac, third-party apps like VLC for more features, and cloud storage services ...
For the first few years, the HomePod exclusively supported Apple Music and AirPlay. It was not possible for third-party music apps to integrate with the device. In 2020, Apple did a HomePod Siri music ...