Connect Uniti Atom to Alexa

Hello everyone. I asked this before and didn’t get too far. I have both mine and my wife’s Android phones talking to the Unity Atom. I have both my Android Tablet and my wife’s iPad also happily streaming Spotify . I would still like to get my Alexa connected but she tells me that she can’t see any bluetooth speakers.

I know that it is all is set up because I have a Mac Mini on my desk and it can see the Unit Atom as a bluetooth speaker.

So, how do I get Alexa to see it please?
David