Implement complete firebase phone number authorization for iOS

To implement Firebase phone number authentication in your iOS app, you can follow these general steps:

Set up your Firebase project and add your iOS app to the project. Follow the Firebase documentation for iOS to get started.
Add the Firebase Authentication SDK to your iOS project. You can do this by adding the following line to your Podfile and running pod install:

pod 'Firebase/Auth'

Set up the phone number authentication provider in the Firebase console. Go to the Firebase console, select your project, and navigate to the Authentication section. Under the Sign-in Method tab, enable the Phone provider and configure the settings as needed.

Configure your app to handle phone number authentication. In your app's code, you'll need to implement the following steps:
a. Import the Firebase Auth framework:

import FirebaseAuth

b. Present the phone number authentication UI to the user. You can use the PhoneAuthProvider class to initiate the authentication flow and show the default Firebase UI for phone number authentication:

let authUI = FUIAuth.defaultAuthUI()
let phoneProvider = FUIPhoneAuth(authUI: authUI!)
authUI?.providers = [phoneProvider]
phoneProvider.signIn(withPresenting: self, phoneNumber: nil)

c. Handle the authentication response. You can implement the FUIAuthDelegate protocol to handle the authentication response and perform any necessary actions, such as updating the UI or navigating to a different view:

func authUI(_ authUI: FUIAuth, didSignInWith user: User?, error: Error?) {
    if let error = error {
        // Handle error
        return
    }
    // User is signed in
    // Perform necessary actions
}

That's a basic overview of how to implement Firebase phone number authentication in your iOS app. For more detailed instructions and customization options, refer to the Firebase documentation for iOS.

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