How can I play a .webm file on flutter app on iOS (or convert easily to mp3)?

Question

I have .webm3 audio files that I want to play in a flutter mobile app on iOS and eventually Android.

I tried to build a firebase function which could do the conversion but even after the function could find the ffmpeg binary I added, the conversion timed out.

So I'm trying to find a simpler way to play the .webm audio.

Thanks.