By default, Byta sets your download format of a file to be the original format. MP3 will be the only download option available where files with different formats are attached.
How to change your download format of lossless files
When attaching audio to a new Share, attaching Lossless files allows you to select an alternate download format for the recipient.
After attaching your file, click the File Format dropdown on each card. You can select either the original format, WAV or MP3 formats.