ios – Invalid `Podfile` file: undefined methodology `exists?’ for File:Class

I’m going through a difficulty with pod file as under whereas instlling POD in Xcode challenge

Invalid `Podfile` file: undefined methodology `exists?' for File:Class

I did attempt to replace POD model with brew improve cocoapods and likewise adopted under hyperlink

https://dev.to/retyui/fix-a-pod-install-error-undefined-method-exist-for-fileclass-react-native-24ke

However nonetheless no repair.

Please information me what am I doing flawed right here.

under is my POD file

# Uncomment the following line to outline a worldwide platform on your challenge
# platform :ios, '9.0'


flutter_application_path="../bmi_flutter"
    
load File.be a part of(flutter_application_path, '.ios', 'Flutter', 'podhelper.rb')

goal 'MixedNativeApp' do
  # Remark the following line in the event you do not need to use dynamic frameworks
  use_frameworks!
  install_all_flutter_pods(flutter_application_path)
  # Pods for MixedNativeApp

  goal 'MixedNativeAppTests' do
    inherit! :search_paths
    # Pods for testing
  finish

  goal 'MixedNativeAppUITests' do
    # Pods for testing
  finish

finish