curl --request GET \
  --url https://api.coldsend.pro/api/public/v1/campaigns/{campaign_id}/leads \
  --header 'X-API-Key: <api-key>'

{
  "success": true,
  "message": "<string>",
  "leads": [
    {
      "lead_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
      "batch_id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
      "email": "<string>",
      "first_name": "<string>",
      "last_name": "<string>",
      "company": "<string>",
      "status": "<string>",
      "last_contacted_at": "2023-11-07T05:31:56Z",
      "opened_at": "2023-11-07T05:31:56Z",
      "replied_at": "2023-11-07T05:31:56Z",
      "created_at": "2023-11-07T05:31:56Z",
      "custom_fields": {},
      "sequence_step": 0,
      "email_opened": false,
      "email_replied": false,
      "unsubscribed": false
    }
  ],
  "pagination": {
    "page": 123,
    "limit": 123,
    "total": 123,
    "pages": 123,
    "has_next": true,
    "has_prev": true
  }
}