curl "https://api2.ecomailapp.cz/pipelines/42/actions/abc-123" \
  -H "key: YOUR_API_KEY" \
  -H "Content-Type: application/json"

$pipelineId = 42;
$actionId = 'abc-123';
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, "https://api2.ecomailapp.cz/pipelines/{$pipelineId}/actions/{$actionId}");
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);

{
  "data": {
    "id": "abc-123",
    "type": "mail",
    "properties": {
      "name": "Welcome email",
      "template": 42
    },
    "next": ["def-456"]
  }
}

{
  "message": "Action not found"
}