I was able to play a simple sound this line of code:
SystemSound.play(SystemSoundType.click);
How can I play a customized sound?
L
[Answer updated: this approach doesn't work, see comments] You can use the video_player plugin maintained by the Flutter team. It can reproduce many kinds of media across platforms, including sound files. More specifically, you may want to use the the VideoPlayerController class.
eg.
_controller = VideoPlayerController.network('https://www.example.com/soundsFile.wav');
_controller.play();