ShowFlutterViewController.swift

import UIKit
import Flutter
import FlutterPluginRegistrant

class ShowFlutterViewControler: UIViewController{
  
  
  func showFlutter(){
        let flutterEnggine = (UIApplication.shared.delegate as! AppDelegate).flutter_engine
        let flutterController = FlutterViewController(engine:flutterEnggine,nibName:nil,bundle:nil)
        
        //start
        //if your have scrollview in your flutter app
        if #available(iOS 13.0, *) {
            flutterController.isModalInPresentation = false
        } else {
            // Fallback on earlier versions
        }
        flutterController.modalPresentationStyle = .fullScreen
        //end
        self.present(flutterController, animated: true, completion: nil)
    }
}