The AppState SDK is currently available for iOS and macOS and required iOS 14+ or macOS 12+. You can integrate it via Swift Package Manager (SPM) to add it to all of your targets.
After setting up your apps on AppState, go to its info screen, copy the ID and paste it into your project in Xcode. This ID is used by AppState to fetch all currently published notifications.
A comprehensive guide on how to integrate the SDK is available on GitHub.