[villasv]

You can, it's just very convoluted.

You can set up billing alarms and use alarms as triggers for actions.

[VPenkov]

One of those stories that get posted every other month about "How I racked up $xx000 bill for Firebase" explained that they had billing alarms but they weren't exactly real time.

Also, you might be the main/only site administrator, in which case falling asleep might end up badly for you.