Cannot find Roon Server (NAD/ BlueNode)

Your Roon Server should have been installed on your MacBook - it’s not on the NAD (which cannot act as a Roon Server - it is a Roon endpoint).

Check to see if the Roon Server app has been installed on your MacBook (in addition to the Roon app - which is now just the Roon User Interface and Control component), and start it running.