Firebase authentication issue - An internal error has occurred, print and inspect the error details for more information

I have used Firebase authentication to receive an OTP for the verification of the user. For that, I have used following method,

        PhoneAuthProvider.provider().verifyPhoneNumber(phoneNumber, uiDelegate: nil) { (verificationID, error) in
      if let error = error {
        showAlert(error.localizedDescription)
        return
      }

      print(verificationID)
    }

Now, the issue is whenever we test release build from test flight in our devices, we are successfully authenticated but when we submit same build for the review team of Apple, they are facing following error,

An internal error has occurred, print and inspect the error details for more information.

Kindly help me how to regenerate above issue from my side, and solve it.