Using the Speaker endpoint to start playing Spotify on my "virtual" speaker

Is it possible to use the Speaker Endpoint to start playing Spotify via an Alexa command on this Item? The reason why I would like to do this, my Denon Heos speaker has not yet a full Spotify-integration, but when using the Spotify Connect Binding I can still access and control it. So the idea would be to create a new Speaker Endpoint in Openhab and internally control it via Spotify Connect.
Unfortunately, I couldn’t find in the Speaker endpoint documentation any link to the source that’s set via an Alexa command. There’s an InputController and a ChannelController, but also when checking the offical Alexa documentation Spotify is not a viable option on these.
Did anyone use yet the Speaker Endpoint, set it as default Speaker for Alexa and then select Spotify on it?

Best,
Tobias.

Can you provide more details such as the item definition you want to expose to Alexa?