All available versions of this package are marked as deprecated. The reason you are able to discover this package in the Unity registry view is because release managers marked it as _isDiscoverable_ in the editor manifest (Unity.app > Contents > Resources > Package Manager > Editor > manifest.json)
"com.unity.zivart-player": {
"isDiscoverable": true,
"version": "2.1.0",
"mustBeBundled": true,
"minimumVersion": "2.1.0"
}