Hi @Gilbert_Martin,
as far as I understood the M23 is Roon Ready. It supports different modes and one if the is the Roon Readyness. This information I found here:
https://www.fiio.com/newsinfo/908672.html
This means the M23 can be used as End Point and DAC for Roon. There is a thread in the Roon forum regarding M23 Roon readyness.
As far as I understand (as I don’t know the M23) it can control Roon as it is Roon Ready. If you connect from there to your AVM60 with an analog cable you should be able to playback the output of the M23 on the AVM. But you can also always control playback from a phone, iPad or PC using the Roon remote App.
As the AVM60 seems to be DLNA compatible you can also directly stream from Roon to AVM60 using rooUPnP. In this case the M23 (or phone, pc, iPad) acts as a controller, controlling playback of the AVM60.
rooUPnP sends FLAC streams (without track length in its FLAC header). There are some elder DLNA receivers out in the wild that are not able to process these FLAC streams but only FLAC files with the track length included. There is no guarantee that it works with your Anthem AVR60! If it did not work I offer a refund.
A list of the devices working with rooUPnP you can find in my download area.
I hope this helps. But please feel free to ask further questions.
Best DrCWO