Hi,
Have you checked the connection center?
If not, you may try via adding a workspace, which is also instructed to provide the list of managed resources available to you on your macOS device.
Add a workspace
https://learn.microsoft.com/en-us/windows-server/remote/remote-desktop-services/clients/remote-desktop-mac#add-a-workspace
Set up email discovery to subscribe to your RDS feed
https://learn.microsoft.com/en-us/windows-server/remote/remote-desktop-services/rds-email-discovery
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Hope this helps and please help to accept as Answer if the response is useful.
Thanks,
Jenny