I hope my blog post at https://gadgeteer.co.za/how-to-test-if-a-self-hosted-alby-hub-wallet-is-connected-and-to-get-an-alert-if-not will help out other Alby Hub self-hosters who want to get alerts if their wallets are offline. This seems to be working fine for me now, and the same theory can be applied for a Python script or even a bash script.