goBackOrForward method
Goes to the history item that is the number of steps away from the current item. Steps is negative if backward and positive if forward.
Official Android API: https://developer.android.com/reference/android/webkit/WebView#goBackOrForward(int)
Official iOS API: https://developer.apple.com/documentation/webkit/wkwebview/1414991-go
Implementation
Future<void> goBackOrForward({required int steps}) async {
Map<String, dynamic> args = <String, dynamic>{};
args.putIfAbsent('steps', () => steps);
await _channel.invokeMethod('goBackOrForward', args);
}