Firebase OAuth client ID provided is either invalid Error

I have been using Firebase Auth (phone) in the app for a long time and have never had a problem

Today a user got that error on iOS device

The OAuth client ID provided is either invalid or does not match the specified API key

Since only one user got this error, I need to debug this carefully

PhoneAuthProvider.provider().verifyPhoneNumber(
    number.getFormattedPhoneNumber(format: .E164)!, 
    uiDelegate: nil, 
    completion: { verificationID, error in

        DispatchQueue.main.async {
            if let error = error {
                //print error
            }

            //logic
        }
    })

I use the above code to verify the phone number

What could cause that error on that user's device?

EDIT: I updated the app with iOS 15 SDK Xcode and the user that had this issue has iOS 14, could be any relation between them?