Base Package

The enum Platforms base package can be downloaded and installed through the Unity Asset Store for free.

enum Platforms

https://assetstore.unity.com/packages/tools/utilities/enum-platforms-244088

Platforms are supported via a separate package and may have an additional cost. Each platform package is ships with base package.

Steam Support

enum Platforms { Steam }

https://github.com/enum-games/Platforms-Steam/releases/tag/v1.0.0