I wanted to set up unified alerts for SQL databases. So I went to Monitor > Alerts and selected my SQL Database. To my surprise, no metrics were available to select.
So I decided to try checking out classic alerts. And all the metrics were there.
If trying to monitor something else in Unified Alerts, you can clearly see that they allow for the selection of metrics. Here's an example of monitoring an App Service Plan.
Any idea on why metrics are missing from SQL Databases in the Unified Alerts experience?