title: Call timer starts counting right after callee accept a call
body: <p>I'm integrating calls in my app. In CallKit documentation  <a href="https://developer.apple.com/documentation/callkit" rel="nofollow noreferrer">https://developer.apple.com/documentation/callkit</a> there is a text:</p>
  
  <blockquote>
    <p>After the call is connected, the system calls the provider(_:perform:) method of the provider delegate. In your implementation, the delegate is responsible for configuring an AVAudioSession and calling fulfill() on the action when finished.</p>
  </blockquote>
  
  <p>And code snippet: </p>
  
  <pre><code>func provider(_ provider: CXProvider, perform action: CXAnswerCallAction) {
      // configure audio session
      action.fulfill()
  }
  </code></pre>
  
  <p>And about <em>fulfill()</em> method:</p>
  
  <blockquote>
    <p>You should only call this method from the implementation of a CXProviderDelegate method.</p>
  </blockquote>
  
  <p>So as I understood, we should call action.fulfill() immediately, after callee accepts a call. </p>
  
  <p>Problem: When device is locked, call timer on native CallKit screen starts counting, but connection is not established yet.</p>
  
  <p>Question: How can I call action.fulfill() or start the timer on the locked  CallKit screen, when connection will be established. Can I control this timer label on locked screen somehow?</p>