Usage of time and time.window or subtract timestamp in notification template

Can someone tell me why the time and time.window params are not working? Tried to use them in the playground (like this Grafana) but it’s not applying but should as described here (docs)…

Background: In my notification template, I am trying to include a link that directs users to the corresponding dashboard. This link should also incorporate a specific time range, namely from three hours before the alert’s timestamp (.StartsAt - 3h) to the actual alert timestamp (.StartsAt). The issue arises from the fact that I cannot perform subtractions directly in the template language, resulting in an error message stating, “function ‘sub’ not defined.