[Observium] Setting up alerts on received power

Hi,

I'd like to setup alerts on RX power levels of my optical interfaces (on juniper and cisco equipment).

In the web interface, this value can be obtained @URL: /device/device=yy/tab=health/metric=dbm/id=xx/

I really can't figure how to properly build an alert checker on this.

Did anyone already set it up ?

Thanks