When an alert rule fires for one of your units, the map tells you at once. You can see which unit it is, where it was, and acknowledge the alert without leaving the map.
A new alert appears as a small card at the bottom left of the map. On a phone it appears at the top. A toast never takes focus and makes no sound.
The chip at the bottom left of the map counts the alerts that need you. It reads "6 open alerts" or "1 open alert", and "recent alerts" when none is open but some fired in the last hour.
Select the chip.
The panel opens above it. It lists the alerts with their title, the unit and the time.

Optional: select Alert centre in the panel header to open the Alert Centre.

The unit with an open alert shows Alarm in its row, with a ring on its marker.
Esc.Select Acknowledge on the toast, in the panel, on the unit row, or on the event card.
The alert leaves the open alerts, and the unit's row loses Alarm.

If it fails, a message reads "Could not acknowledge the alarm". Select Acknowledge again.
Acknowledging records that you saw the alert. It does not resolve what caused it. For what happens to an incident next, see Alert Centre and Incident.
The map keeps its list of open alerts in step with the server. It checks again every 60 seconds, and the panel refreshes every 2 minutes, so a change made by a colleague shows up soon.