title: Why the Flutter phone authentication won't work my real device
body: <p>I have encountered a strange problem. I'm using the Flutter tool to create my iOS app which requires Firebase phone authentication. I was able to make it work on the other app platform without any fuss, but I'm not able to make it work on iOS real device. As per the documentation, I have to register an APN key from the developer account which I did and added my app's bundle ID too. This key I had to upload in my app console in Firebase which I also did. The REVERSE_CLIENT_ID was entered in the project settings in Xcode too, so the simulator version works flawlessly.</p>
  
  <p>However, when it came to make it work on the real iPhone, I get this issue</p>
  
  <pre><code>flutter: exception code verifyPhoneNumberError message Invalid token.
  </code></pre>
  
  <p>I just am not able to make out what the issue is. One thing to note is that I had created a native Swift version using same APN key with different App ID for test purpose. Could this be a cause? Should I create a new APN key and will that allow my old App ID?</p>