curl --request PATCH \
  --url https://api.mottostreaming.com/streaming/simulcasts/v1/{simulcast_id} \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '{
  "simulcast_id": "<string>",
  "simulcast": {
    "name": "<string>",
    "rtmp_target": {
      "url": "<string>",
      "stream_key": "<string>"
    },
    "srt_target": {
      "url": "<string>"
    }
  },
  "update_mask": "<string>",
  "live_stream_id": "<string>"
}'

{
  "simulcast": {
    "id": "<string>",
    "name": "<string>",
    "status": "SIMULCAST_STATUS_UNSPECIFIED",
    "rtmp_target": {
      "url": "<string>",
      "stream_key": "<string>"
    },
    "srt_target": {
      "url": "<string>"
    },
    "is_external": true
  }
}