title: OneSignal VOIP Notifications
body: <p>I have integrated third party <code>OneSignal</code> in my <code>Swift</code> Project. From the documentation provided by <code>OneSignal</code> I am able to send and receive default <code>APNS</code> notification.</p>
  
  <p>But how I can test the <code>VOIP</code> notification using <code>OneSignal</code> also not found proper and complete documentation on this that is why posted this question.</p>
  
  <p>If anybody worked on this let me know the solution.</p>
  
  <p>Thanks in advance.</p>