If you are first getting started you need to enable the zone you are playing to (Settings>Audio…Enable button and set up device).
Then you have to select that zone to play to. There’s a small icon in the lower right corner of the roon window. It should have the name of one of the enabled zones. Select that zone to play to. If you click on that zone icon a box will come up listing all your zones.
It might show up as System Output or perhaps the name of the Audio Engine D2 device.
Getting past the startup… seems to not be intuitive. I am not sure why. And reading the documents will help, but not until one has a foundation from which to build. All in all it is and will be worth the frustration, there are some helpful folks here, others not so much.
Many thanks Rodney. I resolved the problem on my own. Not sure exactly what the issue was first time round. I’ll read the documents - always worthwhile! But I had assumed that initial set up was intuitive which, it wasn’t, at least for me. Thanks to all who offered help.