See wiki https://github.com/EloiStree/2019_01_25_HelloUnityPackageToolbox/wiki
Unity doc: https://docs.unity3d.com/Manual/Packages.html Manifest: https://docs.unity3d.com/Manual/upm-manifestPrj.html

Your own manager Scoped Package registries: https://docs.unity3d.com/Manual/upm-scoped.html