title: How can I send notification from user to user on onesignal?
body: <p>I use OneSignal to send notification from server and users to users. </p>
  
  <p>In my app,users can send notification to eachother.</p>
  
  <p>it is possible with <code>send tag</code>? if so how can i do that? </p>
  
  <p>I do not want to use user ids. (How can find each user ids from another user?)</p>
  
  <p>I want to do that like parse.com. One user setchannel and other user send notification to that channel.</p>
  
  <p>Thanks in advance</p>