curl --request GET \
  --url https://panel.sendcloud.sc/api/v3/event-subscriptions/connections \
  --header 'Authorization: Basic <encoded-value>'

{
  "data": [
    {
      "id": 1,
      "type": "webhook",
      "configuration": {
        "url": "https://example.com/webhooks/sendcloud",
        "auth_type": "bearer",
        "extra_headers": {
          "X-Custom-Header": "my-value"
        }
      },
      "created_at": "2026-01-15T10:30:00Z",
      "updated_at": "2026-01-15T10:30:00Z"
    },
    {
      "id": 2,
      "type": "klaviyo",
      "configuration": {},
      "created_at": "2026-01-16T09:00:00Z",
      "updated_at": "2026-01-16T09:00:00Z"
    }
  ]
}