For picking videos, photos and documents, there are readily available examples on the web to use. However, I didn't find any example on setting up the file types for audios. An example I found for picking document is like below. Is there something similar for audio files?
var customFileType = new FilePickerFileType(new Dictionary<Xamarin.Essentials.DevicePlatform, IEnumerable<string>>
{
{ Xamarin.Essentials.DevicePlatform.iOS, new[] {"com.adobe.pdf", "com.microsoft.word.doc", "org.openxmlformats.wordprocessingml.document" } },
{ Xamarin.Essentials.DevicePlatform.Android, new[] {"application/pdf", "application/doc", "application/document" } }
});