curl --request PUT \
  --url https://api.coldsend.io/api/public/v1/campaigns/{campaign_id} \
  --header 'Content-Type: application/json' \
  --header 'X-API-Key: <api-key>' \
  --data '
{
  "name": "<string>",
  "daily_limit_per_inbox": 50,
  "start_date": "2023-11-07T05:31:56Z",
  "timezone": "<string>",
  "sending_days": [
    123
  ],
  "sending_window_start": 11,
  "sending_window_end": 12,
  "enable_tracking": true,
  "enable_unsubscribe": true,
  "lead_mapping": {},
  "inbox_ids": [
    "3c90c3cc-0d44-4b50-8888-8dd25736052a"
  ],
  "variants": [
    {
      "subject_template": "<string>",
      "email_content": "<string>",
      "variant_name": "A",
      "variant_label": "<string>",
      "distribution_percent": 100
    }
  ],
  "sequences": [
    {
      "step_number": 3,
      "trigger_type": "<string>",
      "wait_days": 15,
      "variants": [
        {
          "email_content": "<string>",
          "variant_name": "A",
          "variant_label": "<string>",
          "subject_template": "<string>",
          "distribution_percent": 100
        }
      ],
      "enable_unsubscribe": true
    }
  ],
  "current_step": 3
}
'

{
  "success": true,
  "message": "<string>",
  "campaign_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "current_step": 123,
  "status": "<string>",
  "updated_at": "2023-11-07T05:31:56Z",
  "inbox_validations": [
    {
      "inbox_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
      "is_valid": true
    }
  ]
}