If you don’t have a Nucleus, shouldn’t the title of your Support Request read something like:
“Issue with accessing Roon subscription on Mac and iPhone”? - I can change it if you like.
When you open Roon on your Mac, are you seeing a screen like this?
Welcome to the community! Based on @Geoff_Coupe’s above response, it looks like you’ve set up Roon Server on your MacBook Air, and have been online and active recently.
Are you still running into issues? Let us know your status, thank you!