Console => New Project
choose IOS=> add this bundle id to the firebase project "Mehdi-Benrefad.FirebaseApp" => download the "GoogleService-Info.plist" file and add it on the project (delete the existing one on the xcode project)
open podfile from Command Line "open -a xcode podfile"
=> add these lines on the file
pod 'Firebase/Analytics'
pod 'Firebase/Database'
pod 'Firebase/Auth'
pod 'Firebase/Core'
=> save the file
=> tap "pod install" on the Command Line
=> check if the firebase importation exist on the app delegate
=> check if this function (FirebaseApp.configure()) exist on the application method
Go to Firebase:"
=>Activate autentication mode with email and password
=> Add a user by adding it's username and password