Hello,
I’m looking for a way to connect Volumio installed on RPI 3B+ to my bluetooth headphones. Of course I did search the forum before asking but the threads are more than 2 years old and no one of the methods described works.
Please advise 
+1 from me too - only in my case my interest is in Bluetooth speakers. At the moment I am using Volumio on a 3A+ as an Internet radio streamer with the 3.5mm jack providing the audio to the AUX input, but completely wireless (apart from powering the Pi of course) would be preferable.
Alternatively, has anyone come up with a digital to Bluetooth audio HAT ? There are several good quality Bluetooth audio CODECs these days that could surely be implemented in hardware.