title: How to invoke a SignalR Core hub method from Postman/WebSocket King
body: <p>I have a SignalR Core hub. I can connect to the same hub using clients like Postman or WebSocket King. But, I am unable to invoke a hub method that expects parameters. The same method can be easily invoked from SignalR JS client. I inspected browser developer tools and extracted the message getting transferred from client to server. When I try to invoke the same method from Postman/WebSocket King with the same message it just don't work.</p>
  <p>Hub method:</p>
  <pre><code>public async Task Subscribe(string[] imeis, string group)
  {
     ...     
  }
  </code></pre>
  <p>Message getting transferred from SignalR client (accessed from browser developer tools):</p>
  <pre><code>{&quot;arguments&quot;:[[10001001],&quot;ALL&quot;],&quot;invocationId&quot;:&quot;0&quot;,&quot;streamIds&quot;:[],&quot;target&quot;:&quot;Subscribe&quot;,&quot;type&quot;:1}
  </code></pre>
  <p>From Postman/WebSocket King, sending this same message does not hit the hub method. Any suggestions?</p>