curl --request DELETE \
  --url https://brew.new/api/v1/triggers \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "triggerEventId": "tri_xxx"
}
'

{
  "error": {
    "code": "TRIGGER_HAS_DEPENDENT_AUTOMATIONS",
    "type": "conflict",
    "message": "Trigger event 'tri_xxx' is referenced by 2 automation(s) and cannot be deleted. Archive or detach them first.",
    "suggestion": "DELETE the referencing automations via DELETE /api/v1/automations then retry.",
    "docs": "https://docs.brew.new/api-reference/api/errors",
    "param": "triggerEventId"
  }
}