How do I implement phone auth using firebase in react native cli?

Initially, I implemented google sign in using Firebase and now I want to implement phone auth in firebase.

Here are the steps, I followed,

1. Enabled the phone sign-in providers.
2. Added SHA certificate fingerprints.
   and Rest followed the code provided by RN Firebase docs

And I'm getting an error like

> Error: [auth/app-not-authorized] This app is not authorized to use Firebase Authentication. Please verify that the correct package name and SHA-1 are configured in the Firebase Console. [ Invalid request fields in play_integrity_token ]
>
> NativeFirebaseError: [auth/app-not-authorized] This app is not authorized to use Firebase Authentication. Please verify that the correct package name and SHA-1 are configured in the Firebase Console. [ Invalid request fields in play_integrity_token ]

How to solve this?

I encounter the same issue and I think I figure it out, which works for me as of June 2023. Here's what i've done:

1. Review SHA-1 and SHA-256 from both locally generated and playstore under Release > Setup > App Integrity > App Signing you set in firebase project settings.
2. Upgrade @react-native-firebase/auth to v17.x.x. Play Integrity is supported starting v17.x.x
3. Test temporary mobile number available online or real mobile number in a real device (not simulator), it seems that Play Integrity only works with a signed release
4. React Native Firebase only suggest to make sure you complete step 1 and 2 but not mentioned "before we begin steps". To be clear, it should be in /app/build.gradle and not /build.gradle as define in firebase docs. See screenshot:

Lastly, make sure when upload .aab in playstore you didn't get warning about safenet deprecation

Hope it helps, otherwise, I would be happy to hear what are updated solutions. As of this writing, I can't find a solution in one place. I had to figure out this myself in different places.