The WebSettingsCompat#setAlgorithmicDarkeningAllowed API is supported on all Android versions in WebView version 105 and later. Previous versions of WebView only supported the API on Android Q and later.
The Jetpack Webkit Library is a static library you can add to your Android application in order to use android.webkit APIs that are not available for older platform versions.
Is there a way to tell which version of the webkit software is used in the Android browser on some specific handset? What would be really great is if there is a URL you can browse to get that information.