title: image in IOS onesignal notification
body: <p>How can I create a notification like 
  <a href="https://i.stack.imgur.com/5SvME.png" rel="nofollow noreferrer">IOS notification with image</a></p>
  
  <p>It is said that you can not specify icon for the IOS but how does this app do it?</p>
  
  <p>I tried with ios_attachments,small_icon,large_icon,big_picture but I did not answer as I expected</p>