What is the alertType in a simulated alert?

The alertType is the type of event to trigger an alert on and defaults to EN_ROUTE.

Options are: EN_ROUTE, LANDED, DIVERTED, CANCELLED, PRE_DEPARTURE_STATUS, PRE_ARRIVAL_STATUS, DEPARTURE_DELAY, ARRIVAL_DELAY, TIME_ADJUSTMENT, DEPARTURE_GATE, ARRIVAL_GATE, GATE_ADJUSTMENT, EQUIPMENT_ADJUSTMENT, BAGGAGE.

The alertType in the simulated alert is restricted to the list given. The list items are the possible events someone could see on a delivery. For example, arrDelayAllowRunway is clarification/refinement of what types of changes the arrDelay subscription would find relevant (e.g. runway delays would trigger events).

  "alertType": {
  "requested": "arrDelayAllowRunway",
  "interpreted": "EN_ROUTE"

If you'd like to test arrival delays, you would ask for an ARRIVAL_DELAY simulated event. Whether you'd get the real event on a runway delay would depend on if you specify the arrDelayAllowRunway subscription.