curl --request POST \
  --url 'https://api.flashcat.cloud/incident/post-mortem/follow-ups/upsert?app_key=' \
  --header 'Content-Type: application/json' \
  --data '
{
  "incident_id": "<string>",
  "follow_up_id": "<string>",
  "participant_ids": [
    123
  ],
  "title": "<string>",
  "description": "<string>"
}
'

{
  "error": {
    "code": "<string>",
    "message": "<string>"
  },
  "data": {
    "status": "drafting",
    "meta": {
      "account_id": 123,
      "incident_id": "<string>",
      "created_at_seconds": 123,
      "updated_at_seconds": 123
    },
    "basics": {
      "post_mortem_title": "<string>",
      "incident_severity": "<string>",
      "incident_start_time_seconds": 123,
      "incident_duration_seconds": 123,
      "incident_commander_id": 123,
      "incident_end_time_seconds": 123,
      "incident_responder_ids": [
        123
      ]
    },
    "summary": {
      "content": "<string>",
      "status": "drafting"
    },
    "timeline": {
      "events": [
        {
          "event_id": "<string>",
          "source": "feed",
          "source_ref": "<string>",
          "at_seconds": 123,
          "event_time_seconds": 123,
          "detail": {}
        }
      ],
      "status": "drafting"
    },
    "impact": {
      "content": "<string>",
      "status": "drafting"
    },
    "contributors": {
      "content": "<string>",
      "status": "drafting"
    },
    "root_cause": {
      "content": "<string>",
      "status": "drafting"
    },
    "mitigators": {
      "content": "<string>",
      "status": "drafting"
    },
    "learnings_and_risks": {
      "content": "<string>",
      "status": "drafting"
    },
    "follow_ups": {
      "follow_ups": [
        {
          "follow_up_id": "<string>",
          "title": "<string>",
          "participant_ids": [
            123
          ],
          "description": "<string>"
        }
      ]
    }
  }
}