Has anyone encountered this issue with Firebase version 8.11.0. I am unsure how to suppress it for my app. Do I need to integrate AppCheck into my project?

[Firebase/Firestore][I-FST000001] AppCheck failed: 'The operation couldn’t be completed. Too many attempts. Underlying error: The operation couldn’t be completed. The server responded with an error: 
 - URL: https://firebaseappcheck.googleapis.com/v1beta/projects/............
 - HTTP status code: 400 
 - Response body: {
  "error": {
    "code": 400,
    "message": "App not registered: ...............",
    "status": "FAILED_PRECONDITION"
  }
}

I had the same issue I solved by adding a p8 file to the firebase app check like this

Create a private key for DeviceCheck

• Create new private key or enable DeviceCheck in your existing key from Apple Developers Account

  

Upload key to DeviceCheck in Firebase console

• Navigate to App Check section of firebase console
• Switch to Apps tab
• Select the iOS app that you would like to integrate DeviceCheck provider with
• Select DeviceCheck
• Provide the private key you created in the previous step
• You can find you private key Id in your Apple developers account
• Save

AppAttest

AppAttest is another built-in AppCheck provider for Apple platforms. Follow below steps to integrate AppAttest in your apps.

You will need Xcode 12.5+ to use App Attest.

Add AppAttest to your firebase project

• Navigate to App Check section of firebase console
• Switch to Apps tab
• Select the iOS app that you would like to integrate AppAttest provider with
• Check AppAttest and save
• Save