https://app.siprtc.io/dist/js/websdk.js

include above script in your html file using

<script src="proxy.php?url=https%3A%2F%2Fapp.siprtc.io%2Fdist%2Fjs%2Fwebsdk.js"></script>

SiprtcWebRTCSDK function helps to initialise websdk and return client object. using this object you can make or answer a call.

var g_client = new SiprtcWebRTCSDK();

function callback(status, event) {
  console.log("Status : " + status)
  console.log(event)
  switch (status) {
    ...
    ...
  }
}