AppFlowy/app_flowy/packages/flowy_editor/ios/Classes/SwiftFlowyEditorPlugin.swift

import Flutter
import UIKit

public class SwiftFlowyEditorPlugin: NSObject, FlutterPlugin {
  public static func register(with registrar: FlutterPluginRegistrar) {
    let channel = FlutterMethodChannel(name: "flowy_editor", binaryMessenger: registrar.messenger())
    let instance = SwiftFlowyEditorPlugin()
    registrar.addMethodCallDelegate(instance, channel: channel)
  }

  public func handle(_ call: FlutterMethodCall, result: @escaping FlutterResult) {
    result("iOS " + UIDevice.current.systemVersion)
  }
}