curl "https://api2.ecomailapp.cz/pipelines/12345/stats-detail?per_page=100&page=1" \
  -H "key: YOUR_API_KEY" \
  -H "Content-Type: application/json"

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, 'https://api2.ecomailapp.cz/pipelines/12345/stats-detail?per_page=100&page=1');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, [
    'key: YOUR_API_KEY',
    'Content-Type: application/json',
]);
$response = curl_exec($ch);
curl_close($ch);

{
  "next_page_url": "https://api2.ecomailapp.cz/pipelines/12345/stats-detail?page=2",
  "total": 2546,
  "per_page": 100,
  "subscribers": {
    "foo@bar.com": {
      "open": 2,
      "send": 3,
      "unsub": 0,
      "soft_bounce": 0,
      "click": 0,
      "hard_bounce": 0,
      "out_of_band": 0,
      "spam": 0
    }
  }
}