curl https://api2.ecomailapp.cz/campaigns/segment/5c36008811e45/stats \
  -H "key: YOUR_API_KEY" \
  -H "Content-Type: application/json"

$segmentId = '5c36008811e45';
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, "https://api2.ecomailapp.cz/campaigns/segment/{$segmentId}/stats");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, [
    'key: YOUR_API_KEY',
    'Content-Type: application/json',
]);
$response = curl_exec($ch);
curl_close($ch);

{
  "stats": {
    "810": {
      "bounce": 0,
      "bounce_rate": 0,
      "click": 3,
      "click_rate": 75,
      "conversions": 2,
      "conversions_value": 2500,
      "delivery": 4,
      "delivery_rate": 100,
      "inject": 4,
      "open": 4,
      "open_rate": 100,
      "spam": 0,
      "spam_rate": 0,
      "unsub": 1,
      "unsub_rate": 25
    }
  }
}