curl --request POST \
  --url http://localhost:3000/v1/admin/notifications/staff/{staffId}/send \
  --header 'Content-Type: application/json' \
  --data '
{
  "title": "<string>",
  "body": "<string>",
  "type": "system",
  "data": {},
  "skipPreferenceCheck": false
}
'

{
  "success": true,
  "sentCount": 123,
  "failedCount": 123,
  "errors": [
    "<string>"
  ]
}