Your best bet is to look for UPnP/DLNA software
DLNA is the industry standard for streaming AV
You are not very specific about your server but if it is Win, MS doesn’t support FLAC
Likewise it won’t play on a PC unless you start using media players supporting both DLNA and FLAC
Win10 is supposed to support FLAC.
Media servers often can be configured for transcoding. If a renderer doesn’t support FLAC, it is transcoded to e.g. WAV.
You might have a look at a...